Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 5652 insertions, 0 deletions

diff --git a/drivers/usb/fotg210/fotg210-hcd.c b/drivers/usb/fotg210/fotg210-hcd.c
new file mode 100644
index 0000000000..7bf810a0c9
--- /dev/null
+++ b/drivers/usb/fotg210/fotg210-hcd.c
@@ -0,0 +1,5652 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Faraday FOTG210 EHCI-like driver
+ *
+ * Copyright (c) 2013 Faraday Technology Corporation
+ *
+ * Author: Yuan-Hsin Chen <yhchen@faraday-tech.com>
+ *	   Feng-Hsin Chiang <john453@faraday-tech.com>
+ *	   Po-Yu Chuang <ratbert.chuang@gmail.com>
+ *
+ * Most of code borrowed from the Linux-3.7 EHCI driver
+ */
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/device.h>
+#include <linux/dmapool.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/sched.h>
+#include <linux/vmalloc.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/hrtimer.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/moduleparam.h>
+#include <linux/dma-mapping.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+
+#include <asm/byteorder.h>
+#include <asm/irq.h>
+#include <asm/unaligned.h>
+
+#include "fotg210.h"
+
+static const char hcd_name[] = "fotg210_hcd";
+
+#undef FOTG210_URB_TRACE
+#define FOTG210_STATS
+
+/* magic numbers that can affect system performance */
+#define FOTG210_TUNE_CERR	3 /* 0-3 qtd retries; 0 == don't stop */
+#define FOTG210_TUNE_RL_HS	4 /* nak throttle; see 4.9 */
+#define FOTG210_TUNE_RL_TT	0
+#define FOTG210_TUNE_MULT_HS	1 /* 1-3 transactions/uframe; 4.10.3 */
+#define FOTG210_TUNE_MULT_TT	1
+
+/* Some drivers think it's safe to schedule isochronous transfers more than 256
+ * ms into the future (partly as a result of an old bug in the scheduling
+ * code).  In an attempt to avoid trouble, we will use a minimum scheduling
+ * length of 512 frames instead of 256.
+ */
+#define FOTG210_TUNE_FLS 1 /* (medium) 512-frame schedule */
+
+/* Initial IRQ latency:  faster than hw default */
+static int log2_irq_thresh; /* 0 to 6 */
+module_param(log2_irq_thresh, int, S_IRUGO);
+MODULE_PARM_DESC(log2_irq_thresh, "log2 IRQ latency, 1-64 microframes");
+
+/* initial park setting:  slower than hw default */
+static unsigned park;
+module_param(park, uint, S_IRUGO);
+MODULE_PARM_DESC(park, "park setting; 1-3 back-to-back async packets");
+
+/* for link power management(LPM) feature */
+static unsigned int hird;
+module_param(hird, int, S_IRUGO);
+MODULE_PARM_DESC(hird, "host initiated resume duration, +1 for each 75us");
+
+#define INTR_MASK (STS_IAA | STS_FATAL | STS_PCD | STS_ERR | STS_INT)
+
+#include "fotg210-hcd.h"
+
+#define fotg210_dbg(fotg210, fmt, args...) \
+	dev_dbg(fotg210_to_hcd(fotg210)->self.controller, fmt, ## args)
+#define fotg210_err(fotg210, fmt, args...) \
+	dev_err(fotg210_to_hcd(fotg210)->self.controller, fmt, ## args)
+#define fotg210_info(fotg210, fmt, args...) \
+	dev_info(fotg210_to_hcd(fotg210)->self.controller, fmt, ## args)
+#define fotg210_warn(fotg210, fmt, args...) \
+	dev_warn(fotg210_to_hcd(fotg210)->self.controller, fmt, ## args)
+
+/* check the values in the HCSPARAMS register (host controller _Structural_
+ * parameters) see EHCI spec, Table 2-4 for each value
+ */
+static void dbg_hcs_params(struct fotg210_hcd *fotg210, char *label)
+{
+	u32 params = fotg210_readl(fotg210, &fotg210->caps->hcs_params);
+
+	fotg210_dbg(fotg210, "%s hcs_params 0x%x ports=%d\n", label, params,
+			HCS_N_PORTS(params));
+}
+
+/* check the values in the HCCPARAMS register (host controller _Capability_
+ * parameters) see EHCI Spec, Table 2-5 for each value
+ */
+static void dbg_hcc_params(struct fotg210_hcd *fotg210, char *label)
+{
+	u32 params = fotg210_readl(fotg210, &fotg210->caps->hcc_params);
+
+	fotg210_dbg(fotg210, "%s hcc_params %04x uframes %s%s\n", label,
+			params,
+			HCC_PGM_FRAMELISTLEN(params) ? "256/512/1024" : "1024",
+			HCC_CANPARK(params) ? " park" : "");
+}
+
+static void __maybe_unused
+dbg_qtd(const char *label, struct fotg210_hcd *fotg210, struct fotg210_qtd *qtd)
+{
+	fotg210_dbg(fotg210, "%s td %p n%08x %08x t%08x p0=%08x\n", label, qtd,
+			hc32_to_cpup(fotg210, &qtd->hw_next),
+			hc32_to_cpup(fotg210, &qtd->hw_alt_next),
+			hc32_to_cpup(fotg210, &qtd->hw_token),
+			hc32_to_cpup(fotg210, &qtd->hw_buf[0]));
+	if (qtd->hw_buf[1])
+		fotg210_dbg(fotg210, "  p1=%08x p2=%08x p3=%08x p4=%08x\n",
+				hc32_to_cpup(fotg210, &qtd->hw_buf[1]),
+				hc32_to_cpup(fotg210, &qtd->hw_buf[2]),
+				hc32_to_cpup(fotg210, &qtd->hw_buf[3]),
+				hc32_to_cpup(fotg210, &qtd->hw_buf[4]));
+}
+
+static void __maybe_unused
+dbg_qh(const char *label, struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	struct fotg210_qh_hw *hw = qh->hw;
+
+	fotg210_dbg(fotg210, "%s qh %p n%08x info %x %x qtd %x\n", label, qh,
+			hw->hw_next, hw->hw_info1, hw->hw_info2,
+			hw->hw_current);
+
+	dbg_qtd("overlay", fotg210, (struct fotg210_qtd *) &hw->hw_qtd_next);
+}
+
+static void __maybe_unused
+dbg_itd(const char *label, struct fotg210_hcd *fotg210, struct fotg210_itd *itd)
+{
+	fotg210_dbg(fotg210, "%s[%d] itd %p, next %08x, urb %p\n", label,
+			itd->frame, itd, hc32_to_cpu(fotg210, itd->hw_next),
+			itd->urb);
+
+	fotg210_dbg(fotg210,
+			"  trans: %08x %08x %08x %08x %08x %08x %08x %08x\n",
+			hc32_to_cpu(fotg210, itd->hw_transaction[0]),
+			hc32_to_cpu(fotg210, itd->hw_transaction[1]),
+			hc32_to_cpu(fotg210, itd->hw_transaction[2]),
+			hc32_to_cpu(fotg210, itd->hw_transaction[3]),
+			hc32_to_cpu(fotg210, itd->hw_transaction[4]),
+			hc32_to_cpu(fotg210, itd->hw_transaction[5]),
+			hc32_to_cpu(fotg210, itd->hw_transaction[6]),
+			hc32_to_cpu(fotg210, itd->hw_transaction[7]));
+
+	fotg210_dbg(fotg210,
+			"  buf:   %08x %08x %08x %08x %08x %08x %08x\n",
+			hc32_to_cpu(fotg210, itd->hw_bufp[0]),
+			hc32_to_cpu(fotg210, itd->hw_bufp[1]),
+			hc32_to_cpu(fotg210, itd->hw_bufp[2]),
+			hc32_to_cpu(fotg210, itd->hw_bufp[3]),
+			hc32_to_cpu(fotg210, itd->hw_bufp[4]),
+			hc32_to_cpu(fotg210, itd->hw_bufp[5]),
+			hc32_to_cpu(fotg210, itd->hw_bufp[6]));
+
+	fotg210_dbg(fotg210, "  index: %d %d %d %d %d %d %d %d\n",
+			itd->index[0], itd->index[1], itd->index[2],
+			itd->index[3], itd->index[4], itd->index[5],
+			itd->index[6], itd->index[7]);
+}
+
+static int __maybe_unused
+dbg_status_buf(char *buf, unsigned len, const char *label, u32 status)
+{
+	return scnprintf(buf, len, "%s%sstatus %04x%s%s%s%s%s%s%s%s%s%s",
+			label, label[0] ? " " : "", status,
+			(status & STS_ASS) ? " Async" : "",
+			(status & STS_PSS) ? " Periodic" : "",
+			(status & STS_RECL) ? " Recl" : "",
+			(status & STS_HALT) ? " Halt" : "",
+			(status & STS_IAA) ? " IAA" : "",
+			(status & STS_FATAL) ? " FATAL" : "",
+			(status & STS_FLR) ? " FLR" : "",
+			(status & STS_PCD) ? " PCD" : "",
+			(status & STS_ERR) ? " ERR" : "",
+			(status & STS_INT) ? " INT" : "");
+}
+
+static int __maybe_unused
+dbg_intr_buf(char *buf, unsigned len, const char *label, u32 enable)
+{
+	return scnprintf(buf, len, "%s%sintrenable %02x%s%s%s%s%s%s",
+			label, label[0] ? " " : "", enable,
+			(enable & STS_IAA) ? " IAA" : "",
+			(enable & STS_FATAL) ? " FATAL" : "",
+			(enable & STS_FLR) ? " FLR" : "",
+			(enable & STS_PCD) ? " PCD" : "",
+			(enable & STS_ERR) ? " ERR" : "",
+			(enable & STS_INT) ? " INT" : "");
+}
+
+static const char *const fls_strings[] = { "1024", "512", "256", "??" };
+
+static int dbg_command_buf(char *buf, unsigned len, const char *label,
+		u32 command)
+{
+	return scnprintf(buf, len,
+			"%s%scommand %07x %s=%d ithresh=%d%s%s%s period=%s%s %s",
+			label, label[0] ? " " : "", command,
+			(command & CMD_PARK) ? " park" : "(park)",
+			CMD_PARK_CNT(command),
+			(command >> 16) & 0x3f,
+			(command & CMD_IAAD) ? " IAAD" : "",
+			(command & CMD_ASE) ? " Async" : "",
+			(command & CMD_PSE) ? " Periodic" : "",
+			fls_strings[(command >> 2) & 0x3],
+			(command & CMD_RESET) ? " Reset" : "",
+			(command & CMD_RUN) ? "RUN" : "HALT");
+}
+
+static char *dbg_port_buf(char *buf, unsigned len, const char *label, int port,
+		u32 status)
+{
+	char *sig;
+
+	/* signaling state */
+	switch (status & (3 << 10)) {
+	case 0 << 10:
+		sig = "se0";
+		break;
+	case 1 << 10:
+		sig = "k";
+		break; /* low speed */
+	case 2 << 10:
+		sig = "j";
+		break;
+	default:
+		sig = "?";
+		break;
+	}
+
+	scnprintf(buf, len, "%s%sport:%d status %06x %d sig=%s%s%s%s%s%s%s%s",
+			label, label[0] ? " " : "", port, status,
+			status >> 25, /*device address */
+			sig,
+			(status & PORT_RESET) ? " RESET" : "",
+			(status & PORT_SUSPEND) ? " SUSPEND" : "",
+			(status & PORT_RESUME) ? " RESUME" : "",
+			(status & PORT_PEC) ? " PEC" : "",
+			(status & PORT_PE) ? " PE" : "",
+			(status & PORT_CSC) ? " CSC" : "",
+			(status & PORT_CONNECT) ? " CONNECT" : "");
+
+	return buf;
+}
+
+/* functions have the "wrong" filename when they're output... */
+#define dbg_status(fotg210, label, status) {			\
+	char _buf[80];						\
+	dbg_status_buf(_buf, sizeof(_buf), label, status);	\
+	fotg210_dbg(fotg210, "%s\n", _buf);			\
+}
+
+#define dbg_cmd(fotg210, label, command) {			\
+	char _buf[80];						\
+	dbg_command_buf(_buf, sizeof(_buf), label, command);	\
+	fotg210_dbg(fotg210, "%s\n", _buf);			\
+}
+
+#define dbg_port(fotg210, label, port, status) {			       \
+	char _buf[80];							       \
+	fotg210_dbg(fotg210, "%s\n",					       \
+			dbg_port_buf(_buf, sizeof(_buf), label, port, status));\
+}
+
+/* troubleshooting help: expose state in debugfs */
+static int debug_async_open(struct inode *, struct file *);
+static int debug_periodic_open(struct inode *, struct file *);
+static int debug_registers_open(struct inode *, struct file *);
+static int debug_async_open(struct inode *, struct file *);
+
+static ssize_t debug_output(struct file*, char __user*, size_t, loff_t*);
+static int debug_close(struct inode *, struct file *);
+
+static const struct file_operations debug_async_fops = {
+	.owner		= THIS_MODULE,
+	.open		= debug_async_open,
+	.read		= debug_output,
+	.release	= debug_close,
+	.llseek		= default_llseek,
+};
+static const struct file_operations debug_periodic_fops = {
+	.owner		= THIS_MODULE,
+	.open		= debug_periodic_open,
+	.read		= debug_output,
+	.release	= debug_close,
+	.llseek		= default_llseek,
+};
+static const struct file_operations debug_registers_fops = {
+	.owner		= THIS_MODULE,
+	.open		= debug_registers_open,
+	.read		= debug_output,
+	.release	= debug_close,
+	.llseek		= default_llseek,
+};
+
+static struct dentry *fotg210_debug_root;
+
+struct debug_buffer {
+	ssize_t (*fill_func)(struct debug_buffer *);	/* fill method */
+	struct usb_bus *bus;
+	struct mutex mutex;	/* protect filling of buffer */
+	size_t count;		/* number of characters filled into buffer */
+	char *output_buf;
+	size_t alloc_size;
+};
+
+static inline char speed_char(u32 scratch)
+{
+	switch (scratch & (3 << 12)) {
+	case QH_FULL_SPEED:
+		return 'f';
+
+	case QH_LOW_SPEED:
+		return 'l';
+
+	case QH_HIGH_SPEED:
+		return 'h';
+
+	default:
+		return '?';
+	}
+}
+
+static inline char token_mark(struct fotg210_hcd *fotg210, __hc32 token)
+{
+	__u32 v = hc32_to_cpu(fotg210, token);
+
+	if (v & QTD_STS_ACTIVE)
+		return '*';
+	if (v & QTD_STS_HALT)
+		return '-';
+	if (!IS_SHORT_READ(v))
+		return ' ';
+	/* tries to advance through hw_alt_next */
+	return '/';
+}
+
+static void qh_lines(struct fotg210_hcd *fotg210, struct fotg210_qh *qh,
+		char **nextp, unsigned *sizep)
+{
+	u32 scratch;
+	u32 hw_curr;
+	struct fotg210_qtd *td;
+	unsigned temp;
+	unsigned size = *sizep;
+	char *next = *nextp;
+	char mark;
+	__le32 list_end = FOTG210_LIST_END(fotg210);
+	struct fotg210_qh_hw *hw = qh->hw;
+
+	if (hw->hw_qtd_next == list_end) /* NEC does this */
+		mark = '@';
+	else
+		mark = token_mark(fotg210, hw->hw_token);
+	if (mark == '/') { /* qh_alt_next controls qh advance? */
+		if ((hw->hw_alt_next & QTD_MASK(fotg210)) ==
+		    fotg210->async->hw->hw_alt_next)
+			mark = '#'; /* blocked */
+		else if (hw->hw_alt_next == list_end)
+			mark = '.'; /* use hw_qtd_next */
+		/* else alt_next points to some other qtd */
+	}
+	scratch = hc32_to_cpup(fotg210, &hw->hw_info1);
+	hw_curr = (mark == '*') ? hc32_to_cpup(fotg210, &hw->hw_current) : 0;
+	temp = scnprintf(next, size,
+			"qh/%p dev%d %cs ep%d %08x %08x(%08x%c %s nak%d)",
+			qh, scratch & 0x007f,
+			speed_char(scratch),
+			(scratch >> 8) & 0x000f,
+			scratch, hc32_to_cpup(fotg210, &hw->hw_info2),
+			hc32_to_cpup(fotg210, &hw->hw_token), mark,
+			(cpu_to_hc32(fotg210, QTD_TOGGLE) & hw->hw_token)
+				? "data1" : "data0",
+			(hc32_to_cpup(fotg210, &hw->hw_alt_next) >> 1) & 0x0f);
+	size -= temp;
+	next += temp;
+
+	/* hc may be modifying the list as we read it ... */
+	list_for_each_entry(td, &qh->qtd_list, qtd_list) {
+		scratch = hc32_to_cpup(fotg210, &td->hw_token);
+		mark = ' ';
+		if (hw_curr == td->qtd_dma)
+			mark = '*';
+		else if (hw->hw_qtd_next == cpu_to_hc32(fotg210, td->qtd_dma))
+			mark = '+';
+		else if (QTD_LENGTH(scratch)) {
+			if (td->hw_alt_next == fotg210->async->hw->hw_alt_next)
+				mark = '#';
+			else if (td->hw_alt_next != list_end)
+				mark = '/';
+		}
+		temp = snprintf(next, size,
+				"\n\t%p%c%s len=%d %08x urb %p",
+				td, mark, ({ char *tmp;
+				switch ((scratch>>8)&0x03) {
+				case 0:
+					tmp = "out";
+					break;
+				case 1:
+					tmp = "in";
+					break;
+				case 2:
+					tmp = "setup";
+					break;
+				default:
+					tmp = "?";
+					break;
+				 } tmp; }),
+				(scratch >> 16) & 0x7fff,
+				scratch,
+				td->urb);
+		if (size < temp)
+			temp = size;
+		size -= temp;
+		next += temp;
+	}
+
+	temp = snprintf(next, size, "\n");
+	if (size < temp)
+		temp = size;
+
+	size -= temp;
+	next += temp;
+
+	*sizep = size;
+	*nextp = next;
+}
+
+static ssize_t fill_async_buffer(struct debug_buffer *buf)
+{
+	struct usb_hcd *hcd;
+	struct fotg210_hcd *fotg210;
+	unsigned long flags;
+	unsigned temp, size;
+	char *next;
+	struct fotg210_qh *qh;
+
+	hcd = bus_to_hcd(buf->bus);
+	fotg210 = hcd_to_fotg210(hcd);
+	next = buf->output_buf;
+	size = buf->alloc_size;
+
+	*next = 0;
+
+	/* dumps a snapshot of the async schedule.
+	 * usually empty except for long-term bulk reads, or head.
+	 * one QH per line, and TDs we know about
+	 */
+	spin_lock_irqsave(&fotg210->lock, flags);
+	for (qh = fotg210->async->qh_next.qh; size > 0 && qh;
+			qh = qh->qh_next.qh)
+		qh_lines(fotg210, qh, &next, &size);
+	if (fotg210->async_unlink && size > 0) {
+		temp = scnprintf(next, size, "\nunlink =\n");
+		size -= temp;
+		next += temp;
+
+		for (qh = fotg210->async_unlink; size > 0 && qh;
+				qh = qh->unlink_next)
+			qh_lines(fotg210, qh, &next, &size);
+	}
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+
+	return strlen(buf->output_buf);
+}
+
+/* count tds, get ep direction */
+static unsigned output_buf_tds_dir(char *buf, struct fotg210_hcd *fotg210,
+		struct fotg210_qh_hw *hw, struct fotg210_qh *qh, unsigned size)
+{
+	u32 scratch = hc32_to_cpup(fotg210, &hw->hw_info1);
+	struct fotg210_qtd *qtd;
+	char *type = "";
+	unsigned temp = 0;
+
+	/* count tds, get ep direction */
+	list_for_each_entry(qtd, &qh->qtd_list, qtd_list) {
+		temp++;
+		switch ((hc32_to_cpu(fotg210, qtd->hw_token) >> 8) & 0x03) {
+		case 0:
+			type = "out";
+			continue;
+		case 1:
+			type = "in";
+			continue;
+		}
+	}
+
+	return scnprintf(buf, size, "(%c%d ep%d%s [%d/%d] q%d p%d)",
+			speed_char(scratch), scratch & 0x007f,
+			(scratch >> 8) & 0x000f, type, qh->usecs,
+			qh->c_usecs, temp, (scratch >> 16) & 0x7ff);
+}
+
+#define DBG_SCHED_LIMIT 64
+static ssize_t fill_periodic_buffer(struct debug_buffer *buf)
+{
+	struct usb_hcd *hcd;
+	struct fotg210_hcd *fotg210;
+	unsigned long flags;
+	union fotg210_shadow p, *seen;
+	unsigned temp, size, seen_count;
+	char *next;
+	unsigned i;
+	__hc32 tag;
+
+	seen = kmalloc_array(DBG_SCHED_LIMIT, sizeof(*seen), GFP_ATOMIC);
+	if (!seen)
+		return 0;
+
+	seen_count = 0;
+
+	hcd = bus_to_hcd(buf->bus);
+	fotg210 = hcd_to_fotg210(hcd);
+	next = buf->output_buf;
+	size = buf->alloc_size;
+
+	temp = scnprintf(next, size, "size = %d\n", fotg210->periodic_size);
+	size -= temp;
+	next += temp;
+
+	/* dump a snapshot of the periodic schedule.
+	 * iso changes, interrupt usually doesn't.
+	 */
+	spin_lock_irqsave(&fotg210->lock, flags);
+	for (i = 0; i < fotg210->periodic_size; i++) {
+		p = fotg210->pshadow[i];
+		if (likely(!p.ptr))
+			continue;
+
+		tag = Q_NEXT_TYPE(fotg210, fotg210->periodic[i]);
+
+		temp = scnprintf(next, size, "%4d: ", i);
+		size -= temp;
+		next += temp;
+
+		do {
+			struct fotg210_qh_hw *hw;
+
+			switch (hc32_to_cpu(fotg210, tag)) {
+			case Q_TYPE_QH:
+				hw = p.qh->hw;
+				temp = scnprintf(next, size, " qh%d-%04x/%p",
+						p.qh->period,
+						hc32_to_cpup(fotg210,
+							&hw->hw_info2)
+							/* uframe masks */
+							& (QH_CMASK | QH_SMASK),
+						p.qh);
+				size -= temp;
+				next += temp;
+				/* don't repeat what follows this qh */
+				for (temp = 0; temp < seen_count; temp++) {
+					if (seen[temp].ptr != p.ptr)
+						continue;
+					if (p.qh->qh_next.ptr) {
+						temp = scnprintf(next, size,
+								" ...");
+						size -= temp;
+						next += temp;
+					}
+					break;
+				}
+				/* show more info the first time around */
+				if (temp == seen_count) {
+					temp = output_buf_tds_dir(next,
+							fotg210, hw,
+							p.qh, size);
+
+					if (seen_count < DBG_SCHED_LIMIT)
+						seen[seen_count++].qh = p.qh;
+				} else
+					temp = 0;
+				tag = Q_NEXT_TYPE(fotg210, hw->hw_next);
+				p = p.qh->qh_next;
+				break;
+			case Q_TYPE_FSTN:
+				temp = scnprintf(next, size,
+						" fstn-%8x/%p",
+						p.fstn->hw_prev, p.fstn);
+				tag = Q_NEXT_TYPE(fotg210, p.fstn->hw_next);
+				p = p.fstn->fstn_next;
+				break;
+			case Q_TYPE_ITD:
+				temp = scnprintf(next, size,
+						" itd/%p", p.itd);
+				tag = Q_NEXT_TYPE(fotg210, p.itd->hw_next);
+				p = p.itd->itd_next;
+				break;
+			}
+			size -= temp;
+			next += temp;
+		} while (p.ptr);
+
+		temp = scnprintf(next, size, "\n");
+		size -= temp;
+		next += temp;
+	}
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	kfree(seen);
+
+	return buf->alloc_size - size;
+}
+#undef DBG_SCHED_LIMIT
+
+static const char *rh_state_string(struct fotg210_hcd *fotg210)
+{
+	switch (fotg210->rh_state) {
+	case FOTG210_RH_HALTED:
+		return "halted";
+	case FOTG210_RH_SUSPENDED:
+		return "suspended";
+	case FOTG210_RH_RUNNING:
+		return "running";
+	case FOTG210_RH_STOPPING:
+		return "stopping";
+	}
+	return "?";
+}
+
+static ssize_t fill_registers_buffer(struct debug_buffer *buf)
+{
+	struct usb_hcd *hcd;
+	struct fotg210_hcd *fotg210;
+	unsigned long flags;
+	unsigned temp, size, i;
+	char *next, scratch[80];
+	static const char fmt[] = "%*s\n";
+	static const char label[] = "";
+
+	hcd = bus_to_hcd(buf->bus);
+	fotg210 = hcd_to_fotg210(hcd);
+	next = buf->output_buf;
+	size = buf->alloc_size;
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+
+	if (!HCD_HW_ACCESSIBLE(hcd)) {
+		size = scnprintf(next, size,
+				"bus %s, device %s\n"
+				"%s\n"
+				"SUSPENDED(no register access)\n",
+				hcd->self.controller->bus->name,
+				dev_name(hcd->self.controller),
+				hcd->product_desc);
+		goto done;
+	}
+
+	/* Capability Registers */
+	i = HC_VERSION(fotg210, fotg210_readl(fotg210,
+			&fotg210->caps->hc_capbase));
+	temp = scnprintf(next, size,
+			"bus %s, device %s\n"
+			"%s\n"
+			"EHCI %x.%02x, rh state %s\n",
+			hcd->self.controller->bus->name,
+			dev_name(hcd->self.controller),
+			hcd->product_desc,
+			i >> 8, i & 0x0ff, rh_state_string(fotg210));
+	size -= temp;
+	next += temp;
+
+	/* FIXME interpret both types of params */
+	i = fotg210_readl(fotg210, &fotg210->caps->hcs_params);
+	temp = scnprintf(next, size, "structural params 0x%08x\n", i);
+	size -= temp;
+	next += temp;
+
+	i = fotg210_readl(fotg210, &fotg210->caps->hcc_params);
+	temp = scnprintf(next, size, "capability params 0x%08x\n", i);
+	size -= temp;
+	next += temp;
+
+	/* Operational Registers */
+	temp = dbg_status_buf(scratch, sizeof(scratch), label,
+			fotg210_readl(fotg210, &fotg210->regs->status));
+	temp = scnprintf(next, size, fmt, temp, scratch);
+	size -= temp;
+	next += temp;
+
+	temp = dbg_command_buf(scratch, sizeof(scratch), label,
+			fotg210_readl(fotg210, &fotg210->regs->command));
+	temp = scnprintf(next, size, fmt, temp, scratch);
+	size -= temp;
+	next += temp;
+
+	temp = dbg_intr_buf(scratch, sizeof(scratch), label,
+			fotg210_readl(fotg210, &fotg210->regs->intr_enable));
+	temp = scnprintf(next, size, fmt, temp, scratch);
+	size -= temp;
+	next += temp;
+
+	temp = scnprintf(next, size, "uframe %04x\n",
+			fotg210_read_frame_index(fotg210));
+	size -= temp;
+	next += temp;
+
+	if (fotg210->async_unlink) {
+		temp = scnprintf(next, size, "async unlink qh %p\n",
+				fotg210->async_unlink);
+		size -= temp;
+		next += temp;
+	}
+
+#ifdef FOTG210_STATS
+	temp = scnprintf(next, size,
+			"irq normal %ld err %ld iaa %ld(lost %ld)\n",
+			fotg210->stats.normal, fotg210->stats.error,
+			fotg210->stats.iaa, fotg210->stats.lost_iaa);
+	size -= temp;
+	next += temp;
+
+	temp = scnprintf(next, size, "complete %ld unlink %ld\n",
+			fotg210->stats.complete, fotg210->stats.unlink);
+	size -= temp;
+	next += temp;
+#endif
+
+done:
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+
+	return buf->alloc_size - size;
+}
+
+static struct debug_buffer
+*alloc_buffer(struct usb_bus *bus, ssize_t (*fill_func)(struct debug_buffer *))
+{
+	struct debug_buffer *buf;
+
+	buf = kzalloc(sizeof(struct debug_buffer), GFP_KERNEL);
+
+	if (buf) {
+		buf->bus = bus;
+		buf->fill_func = fill_func;
+		mutex_init(&buf->mutex);
+		buf->alloc_size = PAGE_SIZE;
+	}
+
+	return buf;
+}
+
+static int fill_buffer(struct debug_buffer *buf)
+{
+	int ret = 0;
+
+	if (!buf->output_buf)
+		buf->output_buf = vmalloc(buf->alloc_size);
+
+	if (!buf->output_buf) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = buf->fill_func(buf);
+
+	if (ret >= 0) {
+		buf->count = ret;
+		ret = 0;
+	}
+
+out:
+	return ret;
+}
+
+static ssize_t debug_output(struct file *file, char __user *user_buf,
+		size_t len, loff_t *offset)
+{
+	struct debug_buffer *buf = file->private_data;
+	int ret = 0;
+
+	mutex_lock(&buf->mutex);
+	if (buf->count == 0) {
+		ret = fill_buffer(buf);
+		if (ret != 0) {
+			mutex_unlock(&buf->mutex);
+			goto out;
+		}
+	}
+	mutex_unlock(&buf->mutex);
+
+	ret = simple_read_from_buffer(user_buf, len, offset,
+			buf->output_buf, buf->count);
+
+out:
+	return ret;
+
+}
+
+static int debug_close(struct inode *inode, struct file *file)
+{
+	struct debug_buffer *buf = file->private_data;
+
+	if (buf) {
+		vfree(buf->output_buf);
+		kfree(buf);
+	}
+
+	return 0;
+}
+static int debug_async_open(struct inode *inode, struct file *file)
+{
+	file->private_data = alloc_buffer(inode->i_private, fill_async_buffer);
+
+	return file->private_data ? 0 : -ENOMEM;
+}
+
+static int debug_periodic_open(struct inode *inode, struct file *file)
+{
+	struct debug_buffer *buf;
+
+	buf = alloc_buffer(inode->i_private, fill_periodic_buffer);
+	if (!buf)
+		return -ENOMEM;
+
+	buf->alloc_size = (sizeof(void *) == 4 ? 6 : 8)*PAGE_SIZE;
+	file->private_data = buf;
+	return 0;
+}
+
+static int debug_registers_open(struct inode *inode, struct file *file)
+{
+	file->private_data = alloc_buffer(inode->i_private,
+			fill_registers_buffer);
+
+	return file->private_data ? 0 : -ENOMEM;
+}
+
+static inline void create_debug_files(struct fotg210_hcd *fotg210)
+{
+	struct usb_bus *bus = &fotg210_to_hcd(fotg210)->self;
+	struct dentry *root;
+
+	root = debugfs_create_dir(bus->bus_name, fotg210_debug_root);
+
+	debugfs_create_file("async", S_IRUGO, root, bus, &debug_async_fops);
+	debugfs_create_file("periodic", S_IRUGO, root, bus,
+			    &debug_periodic_fops);
+	debugfs_create_file("registers", S_IRUGO, root, bus,
+			    &debug_registers_fops);
+}
+
+static inline void remove_debug_files(struct fotg210_hcd *fotg210)
+{
+	struct usb_bus *bus = &fotg210_to_hcd(fotg210)->self;
+
+	debugfs_lookup_and_remove(bus->bus_name, fotg210_debug_root);
+}
+
+/* handshake - spin reading hc until handshake completes or fails
+ * @ptr: address of hc register to be read
+ * @mask: bits to look at in result of read
+ * @done: value of those bits when handshake succeeds
+ * @usec: timeout in microseconds
+ *
+ * Returns negative errno, or zero on success
+ *
+ * Success happens when the "mask" bits have the specified value (hardware
+ * handshake done).  There are two failure modes:  "usec" have passed (major
+ * hardware flakeout), or the register reads as all-ones (hardware removed).
+ *
+ * That last failure should_only happen in cases like physical cardbus eject
+ * before driver shutdown. But it also seems to be caused by bugs in cardbus
+ * bridge shutdown:  shutting down the bridge before the devices using it.
+ */
+static int handshake(struct fotg210_hcd *fotg210, void __iomem *ptr,
+		u32 mask, u32 done, int usec)
+{
+	u32 result;
+	int ret;
+
+	ret = readl_poll_timeout_atomic(ptr, result,
+					((result & mask) == done ||
+					 result == U32_MAX), 1, usec);
+	if (result == U32_MAX)		/* card removed */
+		return -ENODEV;
+
+	return ret;
+}
+
+/* Force HC to halt state from unknown (EHCI spec section 2.3).
+ * Must be called with interrupts enabled and the lock not held.
+ */
+static int fotg210_halt(struct fotg210_hcd *fotg210)
+{
+	u32 temp;
+
+	spin_lock_irq(&fotg210->lock);
+
+	/* disable any irqs left enabled by previous code */
+	fotg210_writel(fotg210, 0, &fotg210->regs->intr_enable);
+
+	/*
+	 * This routine gets called during probe before fotg210->command
+	 * has been initialized, so we can't rely on its value.
+	 */
+	fotg210->command &= ~CMD_RUN;
+	temp = fotg210_readl(fotg210, &fotg210->regs->command);
+	temp &= ~(CMD_RUN | CMD_IAAD);
+	fotg210_writel(fotg210, temp, &fotg210->regs->command);
+
+	spin_unlock_irq(&fotg210->lock);
+	synchronize_irq(fotg210_to_hcd(fotg210)->irq);
+
+	return handshake(fotg210, &fotg210->regs->status,
+			STS_HALT, STS_HALT, 16 * 125);
+}
+
+/* Reset a non-running (STS_HALT == 1) controller.
+ * Must be called with interrupts enabled and the lock not held.
+ */
+static int fotg210_reset(struct fotg210_hcd *fotg210)
+{
+	int retval;
+	u32 command = fotg210_readl(fotg210, &fotg210->regs->command);
+
+	/* If the EHCI debug controller is active, special care must be
+	 * taken before and after a host controller reset
+	 */
+	if (fotg210->debug && !dbgp_reset_prep(fotg210_to_hcd(fotg210)))
+		fotg210->debug = NULL;
+
+	command |= CMD_RESET;
+	dbg_cmd(fotg210, "reset", command);
+	fotg210_writel(fotg210, command, &fotg210->regs->command);
+	fotg210->rh_state = FOTG210_RH_HALTED;
+	fotg210->next_statechange = jiffies;
+	retval = handshake(fotg210, &fotg210->regs->command,
+			CMD_RESET, 0, 250 * 1000);
+
+	if (retval)
+		return retval;
+
+	if (fotg210->debug)
+		dbgp_external_startup(fotg210_to_hcd(fotg210));
+
+	fotg210->port_c_suspend = fotg210->suspended_ports =
+			fotg210->resuming_ports = 0;
+	return retval;
+}
+
+/* Idle the controller (turn off the schedules).
+ * Must be called with interrupts enabled and the lock not held.
+ */
+static void fotg210_quiesce(struct fotg210_hcd *fotg210)
+{
+	u32 temp;
+
+	if (fotg210->rh_state != FOTG210_RH_RUNNING)
+		return;
+
+	/* wait for any schedule enables/disables to take effect */
+	temp = (fotg210->command << 10) & (STS_ASS | STS_PSS);
+	handshake(fotg210, &fotg210->regs->status, STS_ASS | STS_PSS, temp,
+			16 * 125);
+
+	/* then disable anything that's still active */
+	spin_lock_irq(&fotg210->lock);
+	fotg210->command &= ~(CMD_ASE | CMD_PSE);
+	fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
+	spin_unlock_irq(&fotg210->lock);
+
+	/* hardware can take 16 microframes to turn off ... */
+	handshake(fotg210, &fotg210->regs->status, STS_ASS | STS_PSS, 0,
+			16 * 125);
+}
+
+static void end_unlink_async(struct fotg210_hcd *fotg210);
+static void unlink_empty_async(struct fotg210_hcd *fotg210);
+static void fotg210_work(struct fotg210_hcd *fotg210);
+static void start_unlink_intr(struct fotg210_hcd *fotg210,
+			      struct fotg210_qh *qh);
+static void end_unlink_intr(struct fotg210_hcd *fotg210, struct fotg210_qh *qh);
+
+/* Set a bit in the USBCMD register */
+static void fotg210_set_command_bit(struct fotg210_hcd *fotg210, u32 bit)
+{
+	fotg210->command |= bit;
+	fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
+
+	/* unblock posted write */
+	fotg210_readl(fotg210, &fotg210->regs->command);
+}
+
+/* Clear a bit in the USBCMD register */
+static void fotg210_clear_command_bit(struct fotg210_hcd *fotg210, u32 bit)
+{
+	fotg210->command &= ~bit;
+	fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
+
+	/* unblock posted write */
+	fotg210_readl(fotg210, &fotg210->regs->command);
+}
+
+/* EHCI timer support...  Now using hrtimers.
+ *
+ * Lots of different events are triggered from fotg210->hrtimer.  Whenever
+ * the timer routine runs, it checks each possible event; events that are
+ * currently enabled and whose expiration time has passed get handled.
+ * The set of enabled events is stored as a collection of bitflags in
+ * fotg210->enabled_hrtimer_events, and they are numbered in order of
+ * increasing delay values (ranging between 1 ms and 100 ms).
+ *
+ * Rather than implementing a sorted list or tree of all pending events,
+ * we keep track only of the lowest-numbered pending event, in
+ * fotg210->next_hrtimer_event.  Whenever fotg210->hrtimer gets restarted, its
+ * expiration time is set to the timeout value for this event.
+ *
+ * As a result, events might not get handled right away; the actual delay
+ * could be anywhere up to twice the requested delay.  This doesn't
+ * matter, because none of the events are especially time-critical.  The
+ * ones that matter most all have a delay of 1 ms, so they will be
+ * handled after 2 ms at most, which is okay.  In addition to this, we
+ * allow for an expiration range of 1 ms.
+ */
+
+/* Delay lengths for the hrtimer event types.
+ * Keep this list sorted by delay length, in the same order as
+ * the event types indexed by enum fotg210_hrtimer_event in fotg210.h.
+ */
+static unsigned event_delays_ns[] = {
+	1 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_POLL_ASS */
+	1 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_POLL_PSS */
+	1 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_POLL_DEAD */
+	1125 * NSEC_PER_USEC,	/* FOTG210_HRTIMER_UNLINK_INTR */
+	2 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_FREE_ITDS */
+	6 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_ASYNC_UNLINKS */
+	10 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_IAA_WATCHDOG */
+	10 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_DISABLE_PERIODIC */
+	15 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_DISABLE_ASYNC */
+	100 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_IO_WATCHDOG */
+};
+
+/* Enable a pending hrtimer event */
+static void fotg210_enable_event(struct fotg210_hcd *fotg210, unsigned event,
+		bool resched)
+{
+	ktime_t *timeout = &fotg210->hr_timeouts[event];
+
+	if (resched)
+		*timeout = ktime_add(ktime_get(), event_delays_ns[event]);
+	fotg210->enabled_hrtimer_events |= (1 << event);
+
+	/* Track only the lowest-numbered pending event */
+	if (event < fotg210->next_hrtimer_event) {
+		fotg210->next_hrtimer_event = event;
+		hrtimer_start_range_ns(&fotg210->hrtimer, *timeout,
+				NSEC_PER_MSEC, HRTIMER_MODE_ABS);
+	}
+}
+
+
+/* Poll the STS_ASS status bit; see when it agrees with CMD_ASE */
+static void fotg210_poll_ASS(struct fotg210_hcd *fotg210)
+{
+	unsigned actual, want;
+
+	/* Don't enable anything if the controller isn't running (e.g., died) */
+	if (fotg210->rh_state != FOTG210_RH_RUNNING)
+		return;
+
+	want = (fotg210->command & CMD_ASE) ? STS_ASS : 0;
+	actual = fotg210_readl(fotg210, &fotg210->regs->status) & STS_ASS;
+
+	if (want != actual) {
+
+		/* Poll again later, but give up after about 20 ms */
+		if (fotg210->ASS_poll_count++ < 20) {
+			fotg210_enable_event(fotg210, FOTG210_HRTIMER_POLL_ASS,
+					true);
+			return;
+		}
+		fotg210_dbg(fotg210, "Waited too long for the async schedule status (%x/%x), giving up\n",
+				want, actual);
+	}
+	fotg210->ASS_poll_count = 0;
+
+	/* The status is up-to-date; restart or stop the schedule as needed */
+	if (want == 0) {	/* Stopped */
+		if (fotg210->async_count > 0)
+			fotg210_set_command_bit(fotg210, CMD_ASE);
+
+	} else {		/* Running */
+		if (fotg210->async_count == 0) {
+
+			/* Turn off the schedule after a while */
+			fotg210_enable_event(fotg210,
+					FOTG210_HRTIMER_DISABLE_ASYNC,
+					true);
+		}
+	}
+}
+
+/* Turn off the async schedule after a brief delay */
+static void fotg210_disable_ASE(struct fotg210_hcd *fotg210)
+{
+	fotg210_clear_command_bit(fotg210, CMD_ASE);
+}
+
+
+/* Poll the STS_PSS status bit; see when it agrees with CMD_PSE */
+static void fotg210_poll_PSS(struct fotg210_hcd *fotg210)
+{
+	unsigned actual, want;
+
+	/* Don't do anything if the controller isn't running (e.g., died) */
+	if (fotg210->rh_state != FOTG210_RH_RUNNING)
+		return;
+
+	want = (fotg210->command & CMD_PSE) ? STS_PSS : 0;
+	actual = fotg210_readl(fotg210, &fotg210->regs->status) & STS_PSS;
+
+	if (want != actual) {
+
+		/* Poll again later, but give up after about 20 ms */
+		if (fotg210->PSS_poll_count++ < 20) {
+			fotg210_enable_event(fotg210, FOTG210_HRTIMER_POLL_PSS,
+					true);
+			return;
+		}
+		fotg210_dbg(fotg210, "Waited too long for the periodic schedule status (%x/%x), giving up\n",
+				want, actual);
+	}
+	fotg210->PSS_poll_count = 0;
+
+	/* The status is up-to-date; restart or stop the schedule as needed */
+	if (want == 0) {	/* Stopped */
+		if (fotg210->periodic_count > 0)
+			fotg210_set_command_bit(fotg210, CMD_PSE);
+
+	} else {		/* Running */
+		if (fotg210->periodic_count == 0) {
+
+			/* Turn off the schedule after a while */
+			fotg210_enable_event(fotg210,
+					FOTG210_HRTIMER_DISABLE_PERIODIC,
+					true);
+		}
+	}
+}
+
+/* Turn off the periodic schedule after a brief delay */
+static void fotg210_disable_PSE(struct fotg210_hcd *fotg210)
+{
+	fotg210_clear_command_bit(fotg210, CMD_PSE);
+}
+
+
+/* Poll the STS_HALT status bit; see when a dead controller stops */
+static void fotg210_handle_controller_death(struct fotg210_hcd *fotg210)
+{
+	if (!(fotg210_readl(fotg210, &fotg210->regs->status) & STS_HALT)) {
+
+		/* Give up after a few milliseconds */
+		if (fotg210->died_poll_count++ < 5) {
+			/* Try again later */
+			fotg210_enable_event(fotg210,
+					FOTG210_HRTIMER_POLL_DEAD, true);
+			return;
+		}
+		fotg210_warn(fotg210, "Waited too long for the controller to stop, giving up\n");
+	}
+
+	/* Clean up the mess */
+	fotg210->rh_state = FOTG210_RH_HALTED;
+	fotg210_writel(fotg210, 0, &fotg210->regs->intr_enable);
+	fotg210_work(fotg210);
+	end_unlink_async(fotg210);
+
+	/* Not in process context, so don't try to reset the controller */
+}
+
+
+/* Handle unlinked interrupt QHs once they are gone from the hardware */
+static void fotg210_handle_intr_unlinks(struct fotg210_hcd *fotg210)
+{
+	bool stopped = (fotg210->rh_state < FOTG210_RH_RUNNING);
+
+	/*
+	 * Process all the QHs on the intr_unlink list that were added
+	 * before the current unlink cycle began.  The list is in
+	 * temporal order, so stop when we reach the first entry in the
+	 * current cycle.  But if the root hub isn't running then
+	 * process all the QHs on the list.
+	 */
+	fotg210->intr_unlinking = true;
+	while (fotg210->intr_unlink) {
+		struct fotg210_qh *qh = fotg210->intr_unlink;
+
+		if (!stopped && qh->unlink_cycle == fotg210->intr_unlink_cycle)
+			break;
+		fotg210->intr_unlink = qh->unlink_next;
+		qh->unlink_next = NULL;
+		end_unlink_intr(fotg210, qh);
+	}
+
+	/* Handle remaining entries later */
+	if (fotg210->intr_unlink) {
+		fotg210_enable_event(fotg210, FOTG210_HRTIMER_UNLINK_INTR,
+				true);
+		++fotg210->intr_unlink_cycle;
+	}
+	fotg210->intr_unlinking = false;
+}
+
+
+/* Start another free-iTDs/siTDs cycle */
+static void start_free_itds(struct fotg210_hcd *fotg210)
+{
+	if (!(fotg210->enabled_hrtimer_events &
+			BIT(FOTG210_HRTIMER_FREE_ITDS))) {
+		fotg210->last_itd_to_free = list_entry(
+				fotg210->cached_itd_list.prev,
+				struct fotg210_itd, itd_list);
+		fotg210_enable_event(fotg210, FOTG210_HRTIMER_FREE_ITDS, true);
+	}
+}
+
+/* Wait for controller to stop using old iTDs and siTDs */
+static void end_free_itds(struct fotg210_hcd *fotg210)
+{
+	struct fotg210_itd *itd, *n;
+
+	if (fotg210->rh_state < FOTG210_RH_RUNNING)
+		fotg210->last_itd_to_free = NULL;
+
+	list_for_each_entry_safe(itd, n, &fotg210->cached_itd_list, itd_list) {
+		list_del(&itd->itd_list);
+		dma_pool_free(fotg210->itd_pool, itd, itd->itd_dma);
+		if (itd == fotg210->last_itd_to_free)
+			break;
+	}
+
+	if (!list_empty(&fotg210->cached_itd_list))
+		start_free_itds(fotg210);
+}
+
+
+/* Handle lost (or very late) IAA interrupts */
+static void fotg210_iaa_watchdog(struct fotg210_hcd *fotg210)
+{
+	if (fotg210->rh_state != FOTG210_RH_RUNNING)
+		return;
+
+	/*
+	 * Lost IAA irqs wedge things badly; seen first with a vt8235.
+	 * So we need this watchdog, but must protect it against both
+	 * (a) SMP races against real IAA firing and retriggering, and
+	 * (b) clean HC shutdown, when IAA watchdog was pending.
+	 */
+	if (fotg210->async_iaa) {
+		u32 cmd, status;
+
+		/* If we get here, IAA is *REALLY* late.  It's barely
+		 * conceivable that the system is so busy that CMD_IAAD
+		 * is still legitimately set, so let's be sure it's
+		 * clear before we read STS_IAA.  (The HC should clear
+		 * CMD_IAAD when it sets STS_IAA.)
+		 */
+		cmd = fotg210_readl(fotg210, &fotg210->regs->command);
+
+		/*
+		 * If IAA is set here it either legitimately triggered
+		 * after the watchdog timer expired (_way_ late, so we'll
+		 * still count it as lost) ... or a silicon erratum:
+		 * - VIA seems to set IAA without triggering the IRQ;
+		 * - IAAD potentially cleared without setting IAA.
+		 */
+		status = fotg210_readl(fotg210, &fotg210->regs->status);
+		if ((status & STS_IAA) || !(cmd & CMD_IAAD)) {
+			INCR(fotg210->stats.lost_iaa);
+			fotg210_writel(fotg210, STS_IAA,
+					&fotg210->regs->status);
+		}
+
+		fotg210_dbg(fotg210, "IAA watchdog: status %x cmd %x\n",
+				status, cmd);
+		end_unlink_async(fotg210);
+	}
+}
+
+
+/* Enable the I/O watchdog, if appropriate */
+static void turn_on_io_watchdog(struct fotg210_hcd *fotg210)
+{
+	/* Not needed if the controller isn't running or it's already enabled */
+	if (fotg210->rh_state != FOTG210_RH_RUNNING ||
+			(fotg210->enabled_hrtimer_events &
+			BIT(FOTG210_HRTIMER_IO_WATCHDOG)))
+		return;
+
+	/*
+	 * Isochronous transfers always need the watchdog.
+	 * For other sorts we use it only if the flag is set.
+	 */
+	if (fotg210->isoc_count > 0 || (fotg210->need_io_watchdog &&
+			fotg210->async_count + fotg210->intr_count > 0))
+		fotg210_enable_event(fotg210, FOTG210_HRTIMER_IO_WATCHDOG,
+				true);
+}
+
+
+/* Handler functions for the hrtimer event types.
+ * Keep this array in the same order as the event types indexed by
+ * enum fotg210_hrtimer_event in fotg210.h.
+ */
+static void (*event_handlers[])(struct fotg210_hcd *) = {
+	fotg210_poll_ASS,			/* FOTG210_HRTIMER_POLL_ASS */
+	fotg210_poll_PSS,			/* FOTG210_HRTIMER_POLL_PSS */
+	fotg210_handle_controller_death,	/* FOTG210_HRTIMER_POLL_DEAD */
+	fotg210_handle_intr_unlinks,	/* FOTG210_HRTIMER_UNLINK_INTR */
+	end_free_itds,			/* FOTG210_HRTIMER_FREE_ITDS */
+	unlink_empty_async,		/* FOTG210_HRTIMER_ASYNC_UNLINKS */
+	fotg210_iaa_watchdog,		/* FOTG210_HRTIMER_IAA_WATCHDOG */
+	fotg210_disable_PSE,		/* FOTG210_HRTIMER_DISABLE_PERIODIC */
+	fotg210_disable_ASE,		/* FOTG210_HRTIMER_DISABLE_ASYNC */
+	fotg210_work,			/* FOTG210_HRTIMER_IO_WATCHDOG */
+};
+
+static enum hrtimer_restart fotg210_hrtimer_func(struct hrtimer *t)
+{
+	struct fotg210_hcd *fotg210 =
+			container_of(t, struct fotg210_hcd, hrtimer);
+	ktime_t now;
+	unsigned long events;
+	unsigned long flags;
+	unsigned e;
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+
+	events = fotg210->enabled_hrtimer_events;
+	fotg210->enabled_hrtimer_events = 0;
+	fotg210->next_hrtimer_event = FOTG210_HRTIMER_NO_EVENT;
+
+	/*
+	 * Check each pending event.  If its time has expired, handle
+	 * the event; otherwise re-enable it.
+	 */
+	now = ktime_get();
+	for_each_set_bit(e, &events, FOTG210_HRTIMER_NUM_EVENTS) {
+		if (ktime_compare(now, fotg210->hr_timeouts[e]) >= 0)
+			event_handlers[e](fotg210);
+		else
+			fotg210_enable_event(fotg210, e, false);
+	}
+
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	return HRTIMER_NORESTART;
+}
+
+#define fotg210_bus_suspend NULL
+#define fotg210_bus_resume NULL
+
+static int check_reset_complete(struct fotg210_hcd *fotg210, int index,
+		u32 __iomem *status_reg, int port_status)
+{
+	if (!(port_status & PORT_CONNECT))
+		return port_status;
+
+	/* if reset finished and it's still not enabled -- handoff */
+	if (!(port_status & PORT_PE))
+		/* with integrated TT, there's nobody to hand it to! */
+		fotg210_dbg(fotg210, "Failed to enable port %d on root hub TT\n",
+				index + 1);
+	else
+		fotg210_dbg(fotg210, "port %d reset complete, port enabled\n",
+				index + 1);
+
+	return port_status;
+}
+
+
+/* build "status change" packet (one or two bytes) from HC registers */
+
+static int fotg210_hub_status_data(struct usb_hcd *hcd, char *buf)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+	u32 temp, status;
+	u32 mask;
+	int retval = 1;
+	unsigned long flags;
+
+	/* init status to no-changes */
+	buf[0] = 0;
+
+	/* Inform the core about resumes-in-progress by returning
+	 * a non-zero value even if there are no status changes.
+	 */
+	status = fotg210->resuming_ports;
+
+	mask = PORT_CSC | PORT_PEC;
+	/* PORT_RESUME from hardware ~= PORT_STAT_C_SUSPEND */
+
+	/* no hub change reports (bit 0) for now (power, ...) */
+
+	/* port N changes (bit N)? */
+	spin_lock_irqsave(&fotg210->lock, flags);
+
+	temp = fotg210_readl(fotg210, &fotg210->regs->port_status);
+
+	/*
+	 * Return status information even for ports with OWNER set.
+	 * Otherwise hub_wq wouldn't see the disconnect event when a
+	 * high-speed device is switched over to the companion
+	 * controller by the user.
+	 */
+
+	if ((temp & mask) != 0 || test_bit(0, &fotg210->port_c_suspend) ||
+			(fotg210->reset_done[0] &&
+			time_after_eq(jiffies, fotg210->reset_done[0]))) {
+		buf[0] |= 1 << 1;
+		status = STS_PCD;
+	}
+	/* FIXME autosuspend idle root hubs */
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	return status ? retval : 0;
+}
+
+static void fotg210_hub_descriptor(struct fotg210_hcd *fotg210,
+		struct usb_hub_descriptor *desc)
+{
+	int ports = HCS_N_PORTS(fotg210->hcs_params);
+	u16 temp;
+
+	desc->bDescriptorType = USB_DT_HUB;
+	desc->bPwrOn2PwrGood = 10;	/* fotg210 1.0, 2.3.9 says 20ms max */
+	desc->bHubContrCurrent = 0;
+
+	desc->bNbrPorts = ports;
+	temp = 1 + (ports / 8);
+	desc->bDescLength = 7 + 2 * temp;
+
+	/* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
+	memset(&desc->u.hs.DeviceRemovable[0], 0, temp);
+	memset(&desc->u.hs.DeviceRemovable[temp], 0xff, temp);
+
+	temp = HUB_CHAR_INDV_PORT_OCPM;	/* per-port overcurrent reporting */
+	temp |= HUB_CHAR_NO_LPSM;	/* no power switching */
+	desc->wHubCharacteristics = cpu_to_le16(temp);
+}
+
+static int fotg210_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
+		u16 wIndex, char *buf, u16 wLength)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+	int ports = HCS_N_PORTS(fotg210->hcs_params);
+	u32 __iomem *status_reg = &fotg210->regs->port_status;
+	u32 temp, temp1, status;
+	unsigned long flags;
+	int retval = 0;
+	unsigned selector;
+
+	/*
+	 * FIXME:  support SetPortFeatures USB_PORT_FEAT_INDICATOR.
+	 * HCS_INDICATOR may say we can change LEDs to off/amber/green.
+	 * (track current state ourselves) ... blink for diagnostics,
+	 * power, "this is the one", etc.  EHCI spec supports this.
+	 */
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+	switch (typeReq) {
+	case ClearHubFeature:
+		switch (wValue) {
+		case C_HUB_LOCAL_POWER:
+		case C_HUB_OVER_CURRENT:
+			/* no hub-wide feature/status flags */
+			break;
+		default:
+			goto error;
+		}
+		break;
+	case ClearPortFeature:
+		if (!wIndex || wIndex > ports)
+			goto error;
+		wIndex--;
+		temp = fotg210_readl(fotg210, status_reg);
+		temp &= ~PORT_RWC_BITS;
+
+		/*
+		 * Even if OWNER is set, so the port is owned by the
+		 * companion controller, hub_wq needs to be able to clear
+		 * the port-change status bits (especially
+		 * USB_PORT_STAT_C_CONNECTION).
+		 */
+
+		switch (wValue) {
+		case USB_PORT_FEAT_ENABLE:
+			fotg210_writel(fotg210, temp & ~PORT_PE, status_reg);
+			break;
+		case USB_PORT_FEAT_C_ENABLE:
+			fotg210_writel(fotg210, temp | PORT_PEC, status_reg);
+			break;
+		case USB_PORT_FEAT_SUSPEND:
+			if (temp & PORT_RESET)
+				goto error;
+			if (!(temp & PORT_SUSPEND))
+				break;
+			if ((temp & PORT_PE) == 0)
+				goto error;
+
+			/* resume signaling for 20 msec */
+			fotg210_writel(fotg210, temp | PORT_RESUME, status_reg);
+			fotg210->reset_done[wIndex] = jiffies
+					+ msecs_to_jiffies(USB_RESUME_TIMEOUT);
+			break;
+		case USB_PORT_FEAT_C_SUSPEND:
+			clear_bit(wIndex, &fotg210->port_c_suspend);
+			break;
+		case USB_PORT_FEAT_C_CONNECTION:
+			fotg210_writel(fotg210, temp | PORT_CSC, status_reg);
+			break;
+		case USB_PORT_FEAT_C_OVER_CURRENT:
+			fotg210_writel(fotg210, temp | OTGISR_OVC,
+					&fotg210->regs->otgisr);
+			break;
+		case USB_PORT_FEAT_C_RESET:
+			/* GetPortStatus clears reset */
+			break;
+		default:
+			goto error;
+		}
+		fotg210_readl(fotg210, &fotg210->regs->command);
+		break;
+	case GetHubDescriptor:
+		fotg210_hub_descriptor(fotg210, (struct usb_hub_descriptor *)
+				buf);
+		break;
+	case GetHubStatus:
+		/* no hub-wide feature/status flags */
+		memset(buf, 0, 4);
+		/*cpu_to_le32s ((u32 *) buf); */
+		break;
+	case GetPortStatus:
+		if (!wIndex || wIndex > ports)
+			goto error;
+		wIndex--;
+		status = 0;
+		temp = fotg210_readl(fotg210, status_reg);
+
+		/* wPortChange bits */
+		if (temp & PORT_CSC)
+			status |= USB_PORT_STAT_C_CONNECTION << 16;
+		if (temp & PORT_PEC)
+			status |= USB_PORT_STAT_C_ENABLE << 16;
+
+		temp1 = fotg210_readl(fotg210, &fotg210->regs->otgisr);
+		if (temp1 & OTGISR_OVC)
+			status |= USB_PORT_STAT_C_OVERCURRENT << 16;
+
+		/* whoever resumes must GetPortStatus to complete it!! */
+		if (temp & PORT_RESUME) {
+
+			/* Remote Wakeup received? */
+			if (!fotg210->reset_done[wIndex]) {
+				/* resume signaling for 20 msec */
+				fotg210->reset_done[wIndex] = jiffies
+						+ msecs_to_jiffies(20);
+				/* check the port again */
+				mod_timer(&fotg210_to_hcd(fotg210)->rh_timer,
+						fotg210->reset_done[wIndex]);
+			}
+
+			/* resume completed? */
+			else if (time_after_eq(jiffies,
+					fotg210->reset_done[wIndex])) {
+				clear_bit(wIndex, &fotg210->suspended_ports);
+				set_bit(wIndex, &fotg210->port_c_suspend);
+				fotg210->reset_done[wIndex] = 0;
+
+				/* stop resume signaling */
+				temp = fotg210_readl(fotg210, status_reg);
+				fotg210_writel(fotg210, temp &
+						~(PORT_RWC_BITS | PORT_RESUME),
+						status_reg);
+				clear_bit(wIndex, &fotg210->resuming_ports);
+				retval = handshake(fotg210, status_reg,
+						PORT_RESUME, 0, 2000);/* 2ms */
+				if (retval != 0) {
+					fotg210_err(fotg210,
+							"port %d resume error %d\n",
+							wIndex + 1, retval);
+					goto error;
+				}
+				temp &= ~(PORT_SUSPEND|PORT_RESUME|(3<<10));
+			}
+		}
+
+		/* whoever resets must GetPortStatus to complete it!! */
+		if ((temp & PORT_RESET) && time_after_eq(jiffies,
+				fotg210->reset_done[wIndex])) {
+			status |= USB_PORT_STAT_C_RESET << 16;
+			fotg210->reset_done[wIndex] = 0;
+			clear_bit(wIndex, &fotg210->resuming_ports);
+
+			/* force reset to complete */
+			fotg210_writel(fotg210,
+					temp & ~(PORT_RWC_BITS | PORT_RESET),
+					status_reg);
+			/* REVISIT:  some hardware needs 550+ usec to clear
+			 * this bit; seems too long to spin routinely...
+			 */
+			retval = handshake(fotg210, status_reg,
+					PORT_RESET, 0, 1000);
+			if (retval != 0) {
+				fotg210_err(fotg210, "port %d reset error %d\n",
+						wIndex + 1, retval);
+				goto error;
+			}
+
+			/* see what we found out */
+			temp = check_reset_complete(fotg210, wIndex, status_reg,
+					fotg210_readl(fotg210, status_reg));
+
+			/* restart schedule */
+			fotg210->command |= CMD_RUN;
+			fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
+		}
+
+		if (!(temp & (PORT_RESUME|PORT_RESET))) {
+			fotg210->reset_done[wIndex] = 0;
+			clear_bit(wIndex, &fotg210->resuming_ports);
+		}
+
+		/* transfer dedicated ports to the companion hc */
+		if ((temp & PORT_CONNECT) &&
+				test_bit(wIndex, &fotg210->companion_ports)) {
+			temp &= ~PORT_RWC_BITS;
+			fotg210_writel(fotg210, temp, status_reg);
+			fotg210_dbg(fotg210, "port %d --> companion\n",
+					wIndex + 1);
+			temp = fotg210_readl(fotg210, status_reg);
+		}
+
+		/*
+		 * Even if OWNER is set, there's no harm letting hub_wq
+		 * see the wPortStatus values (they should all be 0 except
+		 * for PORT_POWER anyway).
+		 */
+
+		if (temp & PORT_CONNECT) {
+			status |= USB_PORT_STAT_CONNECTION;
+			status |= fotg210_port_speed(fotg210, temp);
+		}
+		if (temp & PORT_PE)
+			status |= USB_PORT_STAT_ENABLE;
+
+		/* maybe the port was unsuspended without our knowledge */
+		if (temp & (PORT_SUSPEND|PORT_RESUME)) {
+			status |= USB_PORT_STAT_SUSPEND;
+		} else if (test_bit(wIndex, &fotg210->suspended_ports)) {
+			clear_bit(wIndex, &fotg210->suspended_ports);
+			clear_bit(wIndex, &fotg210->resuming_ports);
+			fotg210->reset_done[wIndex] = 0;
+			if (temp & PORT_PE)
+				set_bit(wIndex, &fotg210->port_c_suspend);
+		}
+
+		temp1 = fotg210_readl(fotg210, &fotg210->regs->otgisr);
+		if (temp1 & OTGISR_OVC)
+			status |= USB_PORT_STAT_OVERCURRENT;
+		if (temp & PORT_RESET)
+			status |= USB_PORT_STAT_RESET;
+		if (test_bit(wIndex, &fotg210->port_c_suspend))
+			status |= USB_PORT_STAT_C_SUSPEND << 16;
+
+		if (status & ~0xffff)	/* only if wPortChange is interesting */
+			dbg_port(fotg210, "GetStatus", wIndex + 1, temp);
+		put_unaligned_le32(status, buf);
+		break;
+	case SetHubFeature:
+		switch (wValue) {
+		case C_HUB_LOCAL_POWER:
+		case C_HUB_OVER_CURRENT:
+			/* no hub-wide feature/status flags */
+			break;
+		default:
+			goto error;
+		}
+		break;
+	case SetPortFeature:
+		selector = wIndex >> 8;
+		wIndex &= 0xff;
+
+		if (!wIndex || wIndex > ports)
+			goto error;
+		wIndex--;
+		temp = fotg210_readl(fotg210, status_reg);
+		temp &= ~PORT_RWC_BITS;
+		switch (wValue) {
+		case USB_PORT_FEAT_SUSPEND:
+			if ((temp & PORT_PE) == 0
+					|| (temp & PORT_RESET) != 0)
+				goto error;
+
+			/* After above check the port must be connected.
+			 * Set appropriate bit thus could put phy into low power
+			 * mode if we have hostpc feature
+			 */
+			fotg210_writel(fotg210, temp | PORT_SUSPEND,
+					status_reg);
+			set_bit(wIndex, &fotg210->suspended_ports);
+			break;
+		case USB_PORT_FEAT_RESET:
+			if (temp & PORT_RESUME)
+				goto error;
+			/* line status bits may report this as low speed,
+			 * which can be fine if this root hub has a
+			 * transaction translator built in.
+			 */
+			fotg210_dbg(fotg210, "port %d reset\n", wIndex + 1);
+			temp |= PORT_RESET;
+			temp &= ~PORT_PE;
+
+			/*
+			 * caller must wait, then call GetPortStatus
+			 * usb 2.0 spec says 50 ms resets on root
+			 */
+			fotg210->reset_done[wIndex] = jiffies
+					+ msecs_to_jiffies(50);
+			fotg210_writel(fotg210, temp, status_reg);
+			break;
+
+		/* For downstream facing ports (these):  one hub port is put
+		 * into test mode according to USB2 11.24.2.13, then the hub
+		 * must be reset (which for root hub now means rmmod+modprobe,
+		 * or else system reboot).  See EHCI 2.3.9 and 4.14 for info
+		 * about the EHCI-specific stuff.
+		 */
+		case USB_PORT_FEAT_TEST:
+			if (!selector || selector > 5)
+				goto error;
+			spin_unlock_irqrestore(&fotg210->lock, flags);
+			fotg210_quiesce(fotg210);
+			spin_lock_irqsave(&fotg210->lock, flags);
+
+			/* Put all enabled ports into suspend */
+			temp = fotg210_readl(fotg210, status_reg) &
+				~PORT_RWC_BITS;
+			if (temp & PORT_PE)
+				fotg210_writel(fotg210, temp | PORT_SUSPEND,
+						status_reg);
+
+			spin_unlock_irqrestore(&fotg210->lock, flags);
+			fotg210_halt(fotg210);
+			spin_lock_irqsave(&fotg210->lock, flags);
+
+			temp = fotg210_readl(fotg210, status_reg);
+			temp |= selector << 16;
+			fotg210_writel(fotg210, temp, status_reg);
+			break;
+
+		default:
+			goto error;
+		}
+		fotg210_readl(fotg210, &fotg210->regs->command);
+		break;
+
+	default:
+error:
+		/* "stall" on error */
+		retval = -EPIPE;
+	}
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	return retval;
+}
+
+static void __maybe_unused fotg210_relinquish_port(struct usb_hcd *hcd,
+		int portnum)
+{
+	return;
+}
+
+static int __maybe_unused fotg210_port_handed_over(struct usb_hcd *hcd,
+		int portnum)
+{
+	return 0;
+}
+
+/* There's basically three types of memory:
+ *	- data used only by the HCD ... kmalloc is fine
+ *	- async and periodic schedules, shared by HC and HCD ... these
+ *	  need to use dma_pool or dma_alloc_coherent
+ *	- driver buffers, read/written by HC ... single shot DMA mapped
+ *
+ * There's also "register" data (e.g. PCI or SOC), which is memory mapped.
+ * No memory seen by this driver is pageable.
+ */
+
+/* Allocate the key transfer structures from the previously allocated pool */
+static inline void fotg210_qtd_init(struct fotg210_hcd *fotg210,
+		struct fotg210_qtd *qtd, dma_addr_t dma)
+{
+	memset(qtd, 0, sizeof(*qtd));
+	qtd->qtd_dma = dma;
+	qtd->hw_token = cpu_to_hc32(fotg210, QTD_STS_HALT);
+	qtd->hw_next = FOTG210_LIST_END(fotg210);
+	qtd->hw_alt_next = FOTG210_LIST_END(fotg210);
+	INIT_LIST_HEAD(&qtd->qtd_list);
+}
+
+static struct fotg210_qtd *fotg210_qtd_alloc(struct fotg210_hcd *fotg210,
+		gfp_t flags)
+{
+	struct fotg210_qtd *qtd;
+	dma_addr_t dma;
+
+	qtd = dma_pool_alloc(fotg210->qtd_pool, flags, &dma);
+	if (qtd != NULL)
+		fotg210_qtd_init(fotg210, qtd, dma);
+
+	return qtd;
+}
+
+static inline void fotg210_qtd_free(struct fotg210_hcd *fotg210,
+		struct fotg210_qtd *qtd)
+{
+	dma_pool_free(fotg210->qtd_pool, qtd, qtd->qtd_dma);
+}
+
+
+static void qh_destroy(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	/* clean qtds first, and know this is not linked */
+	if (!list_empty(&qh->qtd_list) || qh->qh_next.ptr) {
+		fotg210_dbg(fotg210, "unused qh not empty!\n");
+		BUG();
+	}
+	if (qh->dummy)
+		fotg210_qtd_free(fotg210, qh->dummy);
+	dma_pool_free(fotg210->qh_pool, qh->hw, qh->qh_dma);
+	kfree(qh);
+}
+
+static struct fotg210_qh *fotg210_qh_alloc(struct fotg210_hcd *fotg210,
+		gfp_t flags)
+{
+	struct fotg210_qh *qh;
+	dma_addr_t dma;
+
+	qh = kzalloc(sizeof(*qh), GFP_ATOMIC);
+	if (!qh)
+		goto done;
+	qh->hw = (struct fotg210_qh_hw *)
+		dma_pool_zalloc(fotg210->qh_pool, flags, &dma);
+	if (!qh->hw)
+		goto fail;
+	qh->qh_dma = dma;
+	INIT_LIST_HEAD(&qh->qtd_list);
+
+	/* dummy td enables safe urb queuing */
+	qh->dummy = fotg210_qtd_alloc(fotg210, flags);
+	if (qh->dummy == NULL) {
+		fotg210_dbg(fotg210, "no dummy td\n");
+		goto fail1;
+	}
+done:
+	return qh;
+fail1:
+	dma_pool_free(fotg210->qh_pool, qh->hw, qh->qh_dma);
+fail:
+	kfree(qh);
+	return NULL;
+}
+
+/* The queue heads and transfer descriptors are managed from pools tied
+ * to each of the "per device" structures.
+ * This is the initialisation and cleanup code.
+ */
+
+static void fotg210_mem_cleanup(struct fotg210_hcd *fotg210)
+{
+	if (fotg210->async)
+		qh_destroy(fotg210, fotg210->async);
+	fotg210->async = NULL;
+
+	if (fotg210->dummy)
+		qh_destroy(fotg210, fotg210->dummy);
+	fotg210->dummy = NULL;
+
+	/* DMA consistent memory and pools */
+	dma_pool_destroy(fotg210->qtd_pool);
+	fotg210->qtd_pool = NULL;
+
+	dma_pool_destroy(fotg210->qh_pool);
+	fotg210->qh_pool = NULL;
+
+	dma_pool_destroy(fotg210->itd_pool);
+	fotg210->itd_pool = NULL;
+
+	if (fotg210->periodic)
+		dma_free_coherent(fotg210_to_hcd(fotg210)->self.controller,
+				fotg210->periodic_size * sizeof(u32),
+				fotg210->periodic, fotg210->periodic_dma);
+	fotg210->periodic = NULL;
+
+	/* shadow periodic table */
+	kfree(fotg210->pshadow);
+	fotg210->pshadow = NULL;
+}
+
+/* remember to add cleanup code (above) if you add anything here */
+static int fotg210_mem_init(struct fotg210_hcd *fotg210, gfp_t flags)
+{
+	int i;
+
+	/* QTDs for control/bulk/intr transfers */
+	fotg210->qtd_pool = dma_pool_create("fotg210_qtd",
+			fotg210_to_hcd(fotg210)->self.controller,
+			sizeof(struct fotg210_qtd),
+			32 /* byte alignment (for hw parts) */,
+			4096 /* can't cross 4K */);
+	if (!fotg210->qtd_pool)
+		goto fail;
+
+	/* QHs for control/bulk/intr transfers */
+	fotg210->qh_pool = dma_pool_create("fotg210_qh",
+			fotg210_to_hcd(fotg210)->self.controller,
+			sizeof(struct fotg210_qh_hw),
+			32 /* byte alignment (for hw parts) */,
+			4096 /* can't cross 4K */);
+	if (!fotg210->qh_pool)
+		goto fail;
+
+	fotg210->async = fotg210_qh_alloc(fotg210, flags);
+	if (!fotg210->async)
+		goto fail;
+
+	/* ITD for high speed ISO transfers */
+	fotg210->itd_pool = dma_pool_create("fotg210_itd",
+			fotg210_to_hcd(fotg210)->self.controller,
+			sizeof(struct fotg210_itd),
+			64 /* byte alignment (for hw parts) */,
+			4096 /* can't cross 4K */);
+	if (!fotg210->itd_pool)
+		goto fail;
+
+	/* Hardware periodic table */
+	fotg210->periodic =
+		dma_alloc_coherent(fotg210_to_hcd(fotg210)->self.controller,
+				fotg210->periodic_size * sizeof(__le32),
+				&fotg210->periodic_dma, 0);
+	if (fotg210->periodic == NULL)
+		goto fail;
+
+	for (i = 0; i < fotg210->periodic_size; i++)
+		fotg210->periodic[i] = FOTG210_LIST_END(fotg210);
+
+	/* software shadow of hardware table */
+	fotg210->pshadow = kcalloc(fotg210->periodic_size, sizeof(void *),
+			flags);
+	if (fotg210->pshadow != NULL)
+		return 0;
+
+fail:
+	fotg210_dbg(fotg210, "couldn't init memory\n");
+	fotg210_mem_cleanup(fotg210);
+	return -ENOMEM;
+}
+/* EHCI hardware queue manipulation ... the core.  QH/QTD manipulation.
+ *
+ * Control, bulk, and interrupt traffic all use "qh" lists.  They list "qtd"
+ * entries describing USB transactions, max 16-20kB/entry (with 4kB-aligned
+ * buffers needed for the larger number).  We use one QH per endpoint, queue
+ * multiple urbs (all three types) per endpoint.  URBs may need several qtds.
+ *
+ * ISO traffic uses "ISO TD" (itd) records, and (along with
+ * interrupts) needs careful scheduling.  Performance improvements can be
+ * an ongoing challenge.  That's in "ehci-sched.c".
+ *
+ * USB 1.1 devices are handled (a) by "companion" OHCI or UHCI root hubs,
+ * or otherwise through transaction translators (TTs) in USB 2.0 hubs using
+ * (b) special fields in qh entries or (c) split iso entries.  TTs will
+ * buffer low/full speed data so the host collects it at high speed.
+ */
+
+/* fill a qtd, returning how much of the buffer we were able to queue up */
+static int qtd_fill(struct fotg210_hcd *fotg210, struct fotg210_qtd *qtd,
+		dma_addr_t buf, size_t len, int token, int maxpacket)
+{
+	int i, count;
+	u64 addr = buf;
+
+	/* one buffer entry per 4K ... first might be short or unaligned */
+	qtd->hw_buf[0] = cpu_to_hc32(fotg210, (u32)addr);
+	qtd->hw_buf_hi[0] = cpu_to_hc32(fotg210, (u32)(addr >> 32));
+	count = 0x1000 - (buf & 0x0fff);	/* rest of that page */
+	if (likely(len < count))		/* ... iff needed */
+		count = len;
+	else {
+		buf +=  0x1000;
+		buf &= ~0x0fff;
+
+		/* per-qtd limit: from 16K to 20K (best alignment) */
+		for (i = 1; count < len && i < 5; i++) {
+			addr = buf;
+			qtd->hw_buf[i] = cpu_to_hc32(fotg210, (u32)addr);
+			qtd->hw_buf_hi[i] = cpu_to_hc32(fotg210,
+					(u32)(addr >> 32));
+			buf += 0x1000;
+			if ((count + 0x1000) < len)
+				count += 0x1000;
+			else
+				count = len;
+		}
+
+		/* short packets may only terminate transfers */
+		if (count != len)
+			count -= (count % maxpacket);
+	}
+	qtd->hw_token = cpu_to_hc32(fotg210, (count << 16) | token);
+	qtd->length = count;
+
+	return count;
+}
+
+static inline void qh_update(struct fotg210_hcd *fotg210,
+		struct fotg210_qh *qh, struct fotg210_qtd *qtd)
+{
+	struct fotg210_qh_hw *hw = qh->hw;
+
+	/* writes to an active overlay are unsafe */
+	BUG_ON(qh->qh_state != QH_STATE_IDLE);
+
+	hw->hw_qtd_next = QTD_NEXT(fotg210, qtd->qtd_dma);
+	hw->hw_alt_next = FOTG210_LIST_END(fotg210);
+
+	/* Except for control endpoints, we make hardware maintain data
+	 * toggle (like OHCI) ... here (re)initialize the toggle in the QH,
+	 * and set the pseudo-toggle in udev. Only usb_clear_halt() will
+	 * ever clear it.
+	 */
+	if (!(hw->hw_info1 & cpu_to_hc32(fotg210, QH_TOGGLE_CTL))) {
+		unsigned is_out, epnum;
+
+		is_out = qh->is_out;
+		epnum = (hc32_to_cpup(fotg210, &hw->hw_info1) >> 8) & 0x0f;
+		if (unlikely(!usb_gettoggle(qh->dev, epnum, is_out))) {
+			hw->hw_token &= ~cpu_to_hc32(fotg210, QTD_TOGGLE);
+			usb_settoggle(qh->dev, epnum, is_out, 1);
+		}
+	}
+
+	hw->hw_token &= cpu_to_hc32(fotg210, QTD_TOGGLE | QTD_STS_PING);
+}
+
+/* if it weren't for a common silicon quirk (writing the dummy into the qh
+ * overlay, so qh->hw_token wrongly becomes inactive/halted), only fault
+ * recovery (including urb dequeue) would need software changes to a QH...
+ */
+static void qh_refresh(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	struct fotg210_qtd *qtd;
+
+	if (list_empty(&qh->qtd_list))
+		qtd = qh->dummy;
+	else {
+		qtd = list_entry(qh->qtd_list.next,
+				struct fotg210_qtd, qtd_list);
+		/*
+		 * first qtd may already be partially processed.
+		 * If we come here during unlink, the QH overlay region
+		 * might have reference to the just unlinked qtd. The
+		 * qtd is updated in qh_completions(). Update the QH
+		 * overlay here.
+		 */
+		if (cpu_to_hc32(fotg210, qtd->qtd_dma) == qh->hw->hw_current) {
+			qh->hw->hw_qtd_next = qtd->hw_next;
+			qtd = NULL;
+		}
+	}
+
+	if (qtd)
+		qh_update(fotg210, qh, qtd);
+}
+
+static void qh_link_async(struct fotg210_hcd *fotg210, struct fotg210_qh *qh);
+
+static void fotg210_clear_tt_buffer_complete(struct usb_hcd *hcd,
+		struct usb_host_endpoint *ep)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+	struct fotg210_qh *qh = ep->hcpriv;
+	unsigned long flags;
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+	qh->clearing_tt = 0;
+	if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list)
+			&& fotg210->rh_state == FOTG210_RH_RUNNING)
+		qh_link_async(fotg210, qh);
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+}
+
+static void fotg210_clear_tt_buffer(struct fotg210_hcd *fotg210,
+		struct fotg210_qh *qh, struct urb *urb, u32 token)
+{
+
+	/* If an async split transaction gets an error or is unlinked,
+	 * the TT buffer may be left in an indeterminate state.  We
+	 * have to clear the TT buffer.
+	 *
+	 * Note: this routine is never called for Isochronous transfers.
+	 */
+	if (urb->dev->tt && !usb_pipeint(urb->pipe) && !qh->clearing_tt) {
+		struct usb_device *tt = urb->dev->tt->hub;
+
+		dev_dbg(&tt->dev,
+				"clear tt buffer port %d, a%d ep%d t%08x\n",
+				urb->dev->ttport, urb->dev->devnum,
+				usb_pipeendpoint(urb->pipe), token);
+
+		if (urb->dev->tt->hub !=
+				fotg210_to_hcd(fotg210)->self.root_hub) {
+			if (usb_hub_clear_tt_buffer(urb) == 0)
+				qh->clearing_tt = 1;
+		}
+	}
+}
+
+static int qtd_copy_status(struct fotg210_hcd *fotg210, struct urb *urb,
+		size_t length, u32 token)
+{
+	int status = -EINPROGRESS;
+
+	/* count IN/OUT bytes, not SETUP (even short packets) */
+	if (likely(QTD_PID(token) != 2))
+		urb->actual_length += length - QTD_LENGTH(token);
+
+	/* don't modify error codes */
+	if (unlikely(urb->unlinked))
+		return status;
+
+	/* force cleanup after short read; not always an error */
+	if (unlikely(IS_SHORT_READ(token)))
+		status = -EREMOTEIO;
+
+	/* serious "can't proceed" faults reported by the hardware */
+	if (token & QTD_STS_HALT) {
+		if (token & QTD_STS_BABBLE) {
+			/* FIXME "must" disable babbling device's port too */
+			status = -EOVERFLOW;
+		/* CERR nonzero + halt --> stall */
+		} else if (QTD_CERR(token)) {
+			status = -EPIPE;
+
+		/* In theory, more than one of the following bits can be set
+		 * since they are sticky and the transaction is retried.
+		 * Which to test first is rather arbitrary.
+		 */
+		} else if (token & QTD_STS_MMF) {
+			/* fs/ls interrupt xfer missed the complete-split */
+			status = -EPROTO;
+		} else if (token & QTD_STS_DBE) {
+			status = (QTD_PID(token) == 1) /* IN ? */
+				? -ENOSR  /* hc couldn't read data */
+				: -ECOMM; /* hc couldn't write data */
+		} else if (token & QTD_STS_XACT) {
+			/* timeout, bad CRC, wrong PID, etc */
+			fotg210_dbg(fotg210, "devpath %s ep%d%s 3strikes\n",
+					urb->dev->devpath,
+					usb_pipeendpoint(urb->pipe),
+					usb_pipein(urb->pipe) ? "in" : "out");
+			status = -EPROTO;
+		} else {	/* unknown */
+			status = -EPROTO;
+		}
+
+		fotg210_dbg(fotg210,
+				"dev%d ep%d%s qtd token %08x --> status %d\n",
+				usb_pipedevice(urb->pipe),
+				usb_pipeendpoint(urb->pipe),
+				usb_pipein(urb->pipe) ? "in" : "out",
+				token, status);
+	}
+
+	return status;
+}
+
+static void fotg210_urb_done(struct fotg210_hcd *fotg210, struct urb *urb,
+		int status)
+__releases(fotg210->lock)
+__acquires(fotg210->lock)
+{
+	if (likely(urb->hcpriv != NULL)) {
+		struct fotg210_qh *qh = (struct fotg210_qh *) urb->hcpriv;
+
+		/* S-mask in a QH means it's an interrupt urb */
+		if ((qh->hw->hw_info2 & cpu_to_hc32(fotg210, QH_SMASK)) != 0) {
+
+			/* ... update hc-wide periodic stats (for usbfs) */
+			fotg210_to_hcd(fotg210)->self.bandwidth_int_reqs--;
+		}
+	}
+
+	if (unlikely(urb->unlinked)) {
+		INCR(fotg210->stats.unlink);
+	} else {
+		/* report non-error and short read status as zero */
+		if (status == -EINPROGRESS || status == -EREMOTEIO)
+			status = 0;
+		INCR(fotg210->stats.complete);
+	}
+
+#ifdef FOTG210_URB_TRACE
+	fotg210_dbg(fotg210,
+			"%s %s urb %p ep%d%s status %d len %d/%d\n",
+			__func__, urb->dev->devpath, urb,
+			usb_pipeendpoint(urb->pipe),
+			usb_pipein(urb->pipe) ? "in" : "out",
+			status,
+			urb->actual_length, urb->transfer_buffer_length);
+#endif
+
+	/* complete() can reenter this HCD */
+	usb_hcd_unlink_urb_from_ep(fotg210_to_hcd(fotg210), urb);
+	spin_unlock(&fotg210->lock);
+	usb_hcd_giveback_urb(fotg210_to_hcd(fotg210), urb, status);
+	spin_lock(&fotg210->lock);
+}
+
+static int qh_schedule(struct fotg210_hcd *fotg210, struct fotg210_qh *qh);
+
+/* Process and free completed qtds for a qh, returning URBs to drivers.
+ * Chases up to qh->hw_current.  Returns number of completions called,
+ * indicating how much "real" work we did.
+ */
+static unsigned qh_completions(struct fotg210_hcd *fotg210,
+		struct fotg210_qh *qh)
+{
+	struct fotg210_qtd *last, *end = qh->dummy;
+	struct fotg210_qtd *qtd, *tmp;
+	int last_status;
+	int stopped;
+	unsigned count = 0;
+	u8 state;
+	struct fotg210_qh_hw *hw = qh->hw;
+
+	if (unlikely(list_empty(&qh->qtd_list)))
+		return count;
+
+	/* completions (or tasks on other cpus) must never clobber HALT
+	 * till we've gone through and cleaned everything up, even when
+	 * they add urbs to this qh's queue or mark them for unlinking.
+	 *
+	 * NOTE:  unlinking expects to be done in queue order.
+	 *
+	 * It's a bug for qh->qh_state to be anything other than
+	 * QH_STATE_IDLE, unless our caller is scan_async() or
+	 * scan_intr().
+	 */
+	state = qh->qh_state;
+	qh->qh_state = QH_STATE_COMPLETING;
+	stopped = (state == QH_STATE_IDLE);
+
+rescan:
+	last = NULL;
+	last_status = -EINPROGRESS;
+	qh->needs_rescan = 0;
+
+	/* remove de-activated QTDs from front of queue.
+	 * after faults (including short reads), cleanup this urb
+	 * then let the queue advance.
+	 * if queue is stopped, handles unlinks.
+	 */
+	list_for_each_entry_safe(qtd, tmp, &qh->qtd_list, qtd_list) {
+		struct urb *urb;
+		u32 token = 0;
+
+		urb = qtd->urb;
+
+		/* clean up any state from previous QTD ...*/
+		if (last) {
+			if (likely(last->urb != urb)) {
+				fotg210_urb_done(fotg210, last->urb,
+						last_status);
+				count++;
+				last_status = -EINPROGRESS;
+			}
+			fotg210_qtd_free(fotg210, last);
+			last = NULL;
+		}
+
+		/* ignore urbs submitted during completions we reported */
+		if (qtd == end)
+			break;
+
+		/* hardware copies qtd out of qh overlay */
+		rmb();
+		token = hc32_to_cpu(fotg210, qtd->hw_token);
+
+		/* always clean up qtds the hc de-activated */
+retry_xacterr:
+		if ((token & QTD_STS_ACTIVE) == 0) {
+
+			/* Report Data Buffer Error: non-fatal but useful */
+			if (token & QTD_STS_DBE)
+				fotg210_dbg(fotg210,
+					"detected DataBufferErr for urb %p ep%d%s len %d, qtd %p [qh %p]\n",
+					urb, usb_endpoint_num(&urb->ep->desc),
+					usb_endpoint_dir_in(&urb->ep->desc)
+						? "in" : "out",
+					urb->transfer_buffer_length, qtd, qh);
+
+			/* on STALL, error, and short reads this urb must
+			 * complete and all its qtds must be recycled.
+			 */
+			if ((token & QTD_STS_HALT) != 0) {
+
+				/* retry transaction errors until we
+				 * reach the software xacterr limit
+				 */
+				if ((token & QTD_STS_XACT) &&
+						QTD_CERR(token) == 0 &&
+						++qh->xacterrs < QH_XACTERR_MAX &&
+						!urb->unlinked) {
+					fotg210_dbg(fotg210,
+						"detected XactErr len %zu/%zu retry %d\n",
+						qtd->length - QTD_LENGTH(token),
+						qtd->length,
+						qh->xacterrs);
+
+					/* reset the token in the qtd and the
+					 * qh overlay (which still contains
+					 * the qtd) so that we pick up from
+					 * where we left off
+					 */
+					token &= ~QTD_STS_HALT;
+					token |= QTD_STS_ACTIVE |
+						 (FOTG210_TUNE_CERR << 10);
+					qtd->hw_token = cpu_to_hc32(fotg210,
+							token);
+					wmb();
+					hw->hw_token = cpu_to_hc32(fotg210,
+							token);
+					goto retry_xacterr;
+				}
+				stopped = 1;
+
+			/* magic dummy for some short reads; qh won't advance.
+			 * that silicon quirk can kick in with this dummy too.
+			 *
+			 * other short reads won't stop the queue, including
+			 * control transfers (status stage handles that) or
+			 * most other single-qtd reads ... the queue stops if
+			 * URB_SHORT_NOT_OK was set so the driver submitting
+			 * the urbs could clean it up.
+			 */
+			} else if (IS_SHORT_READ(token) &&
+					!(qtd->hw_alt_next &
+					FOTG210_LIST_END(fotg210))) {
+				stopped = 1;
+			}
+
+		/* stop scanning when we reach qtds the hc is using */
+		} else if (likely(!stopped
+				&& fotg210->rh_state >= FOTG210_RH_RUNNING)) {
+			break;
+
+		/* scan the whole queue for unlinks whenever it stops */
+		} else {
+			stopped = 1;
+
+			/* cancel everything if we halt, suspend, etc */
+			if (fotg210->rh_state < FOTG210_RH_RUNNING)
+				last_status = -ESHUTDOWN;
+
+			/* this qtd is active; skip it unless a previous qtd
+			 * for its urb faulted, or its urb was canceled.
+			 */
+			else if (last_status == -EINPROGRESS && !urb->unlinked)
+				continue;
+
+			/* qh unlinked; token in overlay may be most current */
+			if (state == QH_STATE_IDLE &&
+					cpu_to_hc32(fotg210, qtd->qtd_dma)
+					== hw->hw_current) {
+				token = hc32_to_cpu(fotg210, hw->hw_token);
+
+				/* An unlink may leave an incomplete
+				 * async transaction in the TT buffer.
+				 * We have to clear it.
+				 */
+				fotg210_clear_tt_buffer(fotg210, qh, urb,
+						token);
+			}
+		}
+
+		/* unless we already know the urb's status, collect qtd status
+		 * and update count of bytes transferred.  in common short read
+		 * cases with only one data qtd (including control transfers),
+		 * queue processing won't halt.  but with two or more qtds (for
+		 * example, with a 32 KB transfer), when the first qtd gets a
+		 * short read the second must be removed by hand.
+		 */
+		if (last_status == -EINPROGRESS) {
+			last_status = qtd_copy_status(fotg210, urb,
+					qtd->length, token);
+			if (last_status == -EREMOTEIO &&
+					(qtd->hw_alt_next &
+					FOTG210_LIST_END(fotg210)))
+				last_status = -EINPROGRESS;
+
+			/* As part of low/full-speed endpoint-halt processing
+			 * we must clear the TT buffer (11.17.5).
+			 */
+			if (unlikely(last_status != -EINPROGRESS &&
+					last_status != -EREMOTEIO)) {
+				/* The TT's in some hubs malfunction when they
+				 * receive this request following a STALL (they
+				 * stop sending isochronous packets).  Since a
+				 * STALL can't leave the TT buffer in a busy
+				 * state (if you believe Figures 11-48 - 11-51
+				 * in the USB 2.0 spec), we won't clear the TT
+				 * buffer in this case.  Strictly speaking this
+				 * is a violation of the spec.
+				 */
+				if (last_status != -EPIPE)
+					fotg210_clear_tt_buffer(fotg210, qh,
+							urb, token);
+			}
+		}
+
+		/* if we're removing something not at the queue head,
+		 * patch the hardware queue pointer.
+		 */
+		if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
+			last = list_entry(qtd->qtd_list.prev,
+					struct fotg210_qtd, qtd_list);
+			last->hw_next = qtd->hw_next;
+		}
+
+		/* remove qtd; it's recycled after possible urb completion */
+		list_del(&qtd->qtd_list);
+		last = qtd;
+
+		/* reinit the xacterr counter for the next qtd */
+		qh->xacterrs = 0;
+	}
+
+	/* last urb's completion might still need calling */
+	if (likely(last != NULL)) {
+		fotg210_urb_done(fotg210, last->urb, last_status);
+		count++;
+		fotg210_qtd_free(fotg210, last);
+	}
+
+	/* Do we need to rescan for URBs dequeued during a giveback? */
+	if (unlikely(qh->needs_rescan)) {
+		/* If the QH is already unlinked, do the rescan now. */
+		if (state == QH_STATE_IDLE)
+			goto rescan;
+
+		/* Otherwise we have to wait until the QH is fully unlinked.
+		 * Our caller will start an unlink if qh->needs_rescan is
+		 * set.  But if an unlink has already started, nothing needs
+		 * to be done.
+		 */
+		if (state != QH_STATE_LINKED)
+			qh->needs_rescan = 0;
+	}
+
+	/* restore original state; caller must unlink or relink */
+	qh->qh_state = state;
+
+	/* be sure the hardware's done with the qh before refreshing
+	 * it after fault cleanup, or recovering from silicon wrongly
+	 * overlaying the dummy qtd (which reduces DMA chatter).
+	 */
+	if (stopped != 0 || hw->hw_qtd_next == FOTG210_LIST_END(fotg210)) {
+		switch (state) {
+		case QH_STATE_IDLE:
+			qh_refresh(fotg210, qh);
+			break;
+		case QH_STATE_LINKED:
+			/* We won't refresh a QH that's linked (after the HC
+			 * stopped the queue).  That avoids a race:
+			 *  - HC reads first part of QH;
+			 *  - CPU updates that first part and the token;
+			 *  - HC reads rest of that QH, including token
+			 * Result:  HC gets an inconsistent image, and then
+			 * DMAs to/from the wrong memory (corrupting it).
+			 *
+			 * That should be rare for interrupt transfers,
+			 * except maybe high bandwidth ...
+			 */
+
+			/* Tell the caller to start an unlink */
+			qh->needs_rescan = 1;
+			break;
+		/* otherwise, unlink already started */
+		}
+	}
+
+	return count;
+}
+
+/* reverse of qh_urb_transaction:  free a list of TDs.
+ * used for cleanup after errors, before HC sees an URB's TDs.
+ */
+static void qtd_list_free(struct fotg210_hcd *fotg210, struct urb *urb,
+		struct list_head *head)
+{
+	struct fotg210_qtd *qtd, *temp;
+
+	list_for_each_entry_safe(qtd, temp, head, qtd_list) {
+		list_del(&qtd->qtd_list);
+		fotg210_qtd_free(fotg210, qtd);
+	}
+}
+
+/* create a list of filled qtds for this URB; won't link into qh.
+ */
+static struct list_head *qh_urb_transaction(struct fotg210_hcd *fotg210,
+		struct urb *urb, struct list_head *head, gfp_t flags)
+{
+	struct fotg210_qtd *qtd, *qtd_prev;
+	dma_addr_t buf;
+	int len, this_sg_len, maxpacket;
+	int is_input;
+	u32 token;
+	int i;
+	struct scatterlist *sg;
+
+	/*
+	 * URBs map to sequences of QTDs:  one logical transaction
+	 */
+	qtd = fotg210_qtd_alloc(fotg210, flags);
+	if (unlikely(!qtd))
+		return NULL;
+	list_add_tail(&qtd->qtd_list, head);
+	qtd->urb = urb;
+
+	token = QTD_STS_ACTIVE;
+	token |= (FOTG210_TUNE_CERR << 10);
+	/* for split transactions, SplitXState initialized to zero */
+
+	len = urb->transfer_buffer_length;
+	is_input = usb_pipein(urb->pipe);
+	if (usb_pipecontrol(urb->pipe)) {
+		/* SETUP pid */
+		qtd_fill(fotg210, qtd, urb->setup_dma,
+				sizeof(struct usb_ctrlrequest),
+				token | (2 /* "setup" */ << 8), 8);
+
+		/* ... and always at least one more pid */
+		token ^= QTD_TOGGLE;
+		qtd_prev = qtd;
+		qtd = fotg210_qtd_alloc(fotg210, flags);
+		if (unlikely(!qtd))
+			goto cleanup;
+		qtd->urb = urb;
+		qtd_prev->hw_next = QTD_NEXT(fotg210, qtd->qtd_dma);
+		list_add_tail(&qtd->qtd_list, head);
+
+		/* for zero length DATA stages, STATUS is always IN */
+		if (len == 0)
+			token |= (1 /* "in" */ << 8);
+	}
+
+	/*
+	 * data transfer stage:  buffer setup
+	 */
+	i = urb->num_mapped_sgs;
+	if (len > 0 && i > 0) {
+		sg = urb->sg;
+		buf = sg_dma_address(sg);
+
+		/* urb->transfer_buffer_length may be smaller than the
+		 * size of the scatterlist (or vice versa)
+		 */
+		this_sg_len = min_t(int, sg_dma_len(sg), len);
+	} else {
+		sg = NULL;
+		buf = urb->transfer_dma;
+		this_sg_len = len;
+	}
+
+	if (is_input)
+		token |= (1 /* "in" */ << 8);
+	/* else it's already initted to "out" pid (0 << 8) */
+
+	maxpacket = usb_maxpacket(urb->dev, urb->pipe);
+
+	/*
+	 * buffer gets wrapped in one or more qtds;
+	 * last one may be "short" (including zero len)
+	 * and may serve as a control status ack
+	 */
+	for (;;) {
+		int this_qtd_len;
+
+		this_qtd_len = qtd_fill(fotg210, qtd, buf, this_sg_len, token,
+				maxpacket);
+		this_sg_len -= this_qtd_len;
+		len -= this_qtd_len;
+		buf += this_qtd_len;
+
+		/*
+		 * short reads advance to a "magic" dummy instead of the next
+		 * qtd ... that forces the queue to stop, for manual cleanup.
+		 * (this will usually be overridden later.)
+		 */
+		if (is_input)
+			qtd->hw_alt_next = fotg210->async->hw->hw_alt_next;
+
+		/* qh makes control packets use qtd toggle; maybe switch it */
+		if ((maxpacket & (this_qtd_len + (maxpacket - 1))) == 0)
+			token ^= QTD_TOGGLE;
+
+		if (likely(this_sg_len <= 0)) {
+			if (--i <= 0 || len <= 0)
+				break;
+			sg = sg_next(sg);
+			buf = sg_dma_address(sg);
+			this_sg_len = min_t(int, sg_dma_len(sg), len);
+		}
+
+		qtd_prev = qtd;
+		qtd = fotg210_qtd_alloc(fotg210, flags);
+		if (unlikely(!qtd))
+			goto cleanup;
+		qtd->urb = urb;
+		qtd_prev->hw_next = QTD_NEXT(fotg210, qtd->qtd_dma);
+		list_add_tail(&qtd->qtd_list, head);
+	}
+
+	/*
+	 * unless the caller requires manual cleanup after short reads,
+	 * have the alt_next mechanism keep the queue running after the
+	 * last data qtd (the only one, for control and most other cases).
+	 */
+	if (likely((urb->transfer_flags & URB_SHORT_NOT_OK) == 0 ||
+			usb_pipecontrol(urb->pipe)))
+		qtd->hw_alt_next = FOTG210_LIST_END(fotg210);
+
+	/*
+	 * control requests may need a terminating data "status" ack;
+	 * other OUT ones may need a terminating short packet
+	 * (zero length).
+	 */
+	if (likely(urb->transfer_buffer_length != 0)) {
+		int one_more = 0;
+
+		if (usb_pipecontrol(urb->pipe)) {
+			one_more = 1;
+			token ^= 0x0100;	/* "in" <--> "out"  */
+			token |= QTD_TOGGLE;	/* force DATA1 */
+		} else if (usb_pipeout(urb->pipe)
+				&& (urb->transfer_flags & URB_ZERO_PACKET)
+				&& !(urb->transfer_buffer_length % maxpacket)) {
+			one_more = 1;
+		}
+		if (one_more) {
+			qtd_prev = qtd;
+			qtd = fotg210_qtd_alloc(fotg210, flags);
+			if (unlikely(!qtd))
+				goto cleanup;
+			qtd->urb = urb;
+			qtd_prev->hw_next = QTD_NEXT(fotg210, qtd->qtd_dma);
+			list_add_tail(&qtd->qtd_list, head);
+
+			/* never any data in such packets */
+			qtd_fill(fotg210, qtd, 0, 0, token, 0);
+		}
+	}
+
+	/* by default, enable interrupt on urb completion */
+	if (likely(!(urb->transfer_flags & URB_NO_INTERRUPT)))
+		qtd->hw_token |= cpu_to_hc32(fotg210, QTD_IOC);
+	return head;
+
+cleanup:
+	qtd_list_free(fotg210, urb, head);
+	return NULL;
+}
+
+/* Would be best to create all qh's from config descriptors,
+ * when each interface/altsetting is established.  Unlink
+ * any previous qh and cancel its urbs first; endpoints are
+ * implicitly reset then (data toggle too).
+ * That'd mean updating how usbcore talks to HCDs. (2.7?)
+ */
+
+
+/* Each QH holds a qtd list; a QH is used for everything except iso.
+ *
+ * For interrupt urbs, the scheduler must set the microframe scheduling
+ * mask(s) each time the QH gets scheduled.  For highspeed, that's
+ * just one microframe in the s-mask.  For split interrupt transactions
+ * there are additional complications: c-mask, maybe FSTNs.
+ */
+static struct fotg210_qh *qh_make(struct fotg210_hcd *fotg210, struct urb *urb,
+		gfp_t flags)
+{
+	struct fotg210_qh *qh = fotg210_qh_alloc(fotg210, flags);
+	struct usb_host_endpoint *ep;
+	u32 info1 = 0, info2 = 0;
+	int is_input, type;
+	int maxp = 0;
+	int mult;
+	struct usb_tt *tt = urb->dev->tt;
+	struct fotg210_qh_hw *hw;
+
+	if (!qh)
+		return qh;
+
+	/*
+	 * init endpoint/device data for this QH
+	 */
+	info1 |= usb_pipeendpoint(urb->pipe) << 8;
+	info1 |= usb_pipedevice(urb->pipe) << 0;
+
+	is_input = usb_pipein(urb->pipe);
+	type = usb_pipetype(urb->pipe);
+	ep = usb_pipe_endpoint(urb->dev, urb->pipe);
+	maxp = usb_endpoint_maxp(&ep->desc);
+	mult = usb_endpoint_maxp_mult(&ep->desc);
+
+	/* 1024 byte maxpacket is a hardware ceiling.  High bandwidth
+	 * acts like up to 3KB, but is built from smaller packets.
+	 */
+	if (maxp > 1024) {
+		fotg210_dbg(fotg210, "bogus qh maxpacket %d\n", maxp);
+		goto done;
+	}
+
+	/* Compute interrupt scheduling parameters just once, and save.
+	 * - allowing for high bandwidth, how many nsec/uframe are used?
+	 * - split transactions need a second CSPLIT uframe; same question
+	 * - splits also need a schedule gap (for full/low speed I/O)
+	 * - qh has a polling interval
+	 *
+	 * For control/bulk requests, the HC or TT handles these.
+	 */
+	if (type == PIPE_INTERRUPT) {
+		qh->usecs = NS_TO_US(usb_calc_bus_time(USB_SPEED_HIGH,
+				is_input, 0, mult * maxp));
+		qh->start = NO_FRAME;
+
+		if (urb->dev->speed == USB_SPEED_HIGH) {
+			qh->c_usecs = 0;
+			qh->gap_uf = 0;
+
+			qh->period = urb->interval >> 3;
+			if (qh->period == 0 && urb->interval != 1) {
+				/* NOTE interval 2 or 4 uframes could work.
+				 * But interval 1 scheduling is simpler, and
+				 * includes high bandwidth.
+				 */
+				urb->interval = 1;
+			} else if (qh->period > fotg210->periodic_size) {
+				qh->period = fotg210->periodic_size;
+				urb->interval = qh->period << 3;
+			}
+		} else {
+			int think_time;
+
+			/* gap is f(FS/LS transfer times) */
+			qh->gap_uf = 1 + usb_calc_bus_time(urb->dev->speed,
+					is_input, 0, maxp) / (125 * 1000);
+
+			/* FIXME this just approximates SPLIT/CSPLIT times */
+			if (is_input) {		/* SPLIT, gap, CSPLIT+DATA */
+				qh->c_usecs = qh->usecs + HS_USECS(0);
+				qh->usecs = HS_USECS(1);
+			} else {		/* SPLIT+DATA, gap, CSPLIT */
+				qh->usecs += HS_USECS(1);
+				qh->c_usecs = HS_USECS(0);
+			}
+
+			think_time = tt ? tt->think_time : 0;
+			qh->tt_usecs = NS_TO_US(think_time +
+					usb_calc_bus_time(urb->dev->speed,
+					is_input, 0, maxp));
+			qh->period = urb->interval;
+			if (qh->period > fotg210->periodic_size) {
+				qh->period = fotg210->periodic_size;
+				urb->interval = qh->period;
+			}
+		}
+	}
+
+	/* support for tt scheduling, and access to toggles */
+	qh->dev = urb->dev;
+
+	/* using TT? */
+	switch (urb->dev->speed) {
+	case USB_SPEED_LOW:
+		info1 |= QH_LOW_SPEED;
+		fallthrough;
+
+	case USB_SPEED_FULL:
+		/* EPS 0 means "full" */
+		if (type != PIPE_INTERRUPT)
+			info1 |= (FOTG210_TUNE_RL_TT << 28);
+		if (type == PIPE_CONTROL) {
+			info1 |= QH_CONTROL_EP;		/* for TT */
+			info1 |= QH_TOGGLE_CTL;		/* toggle from qtd */
+		}
+		info1 |= maxp << 16;
+
+		info2 |= (FOTG210_TUNE_MULT_TT << 30);
+
+		/* Some Freescale processors have an erratum in which the
+		 * port number in the queue head was 0..N-1 instead of 1..N.
+		 */
+		if (fotg210_has_fsl_portno_bug(fotg210))
+			info2 |= (urb->dev->ttport-1) << 23;
+		else
+			info2 |= urb->dev->ttport << 23;
+
+		/* set the address of the TT; for TDI's integrated
+		 * root hub tt, leave it zeroed.
+		 */
+		if (tt && tt->hub != fotg210_to_hcd(fotg210)->self.root_hub)
+			info2 |= tt->hub->devnum << 16;
+
+		/* NOTE:  if (PIPE_INTERRUPT) { scheduler sets c-mask } */
+
+		break;
+
+	case USB_SPEED_HIGH:		/* no TT involved */
+		info1 |= QH_HIGH_SPEED;
+		if (type == PIPE_CONTROL) {
+			info1 |= (FOTG210_TUNE_RL_HS << 28);
+			info1 |= 64 << 16;	/* usb2 fixed maxpacket */
+			info1 |= QH_TOGGLE_CTL;	/* toggle from qtd */
+			info2 |= (FOTG210_TUNE_MULT_HS << 30);
+		} else if (type == PIPE_BULK) {
+			info1 |= (FOTG210_TUNE_RL_HS << 28);
+			/* The USB spec says that high speed bulk endpoints
+			 * always use 512 byte maxpacket.  But some device
+			 * vendors decided to ignore that, and MSFT is happy
+			 * to help them do so.  So now people expect to use
+			 * such nonconformant devices with Linux too; sigh.
+			 */
+			info1 |= maxp << 16;
+			info2 |= (FOTG210_TUNE_MULT_HS << 30);
+		} else {		/* PIPE_INTERRUPT */
+			info1 |= maxp << 16;
+			info2 |= mult << 30;
+		}
+		break;
+	default:
+		fotg210_dbg(fotg210, "bogus dev %p speed %d\n", urb->dev,
+				urb->dev->speed);
+done:
+		qh_destroy(fotg210, qh);
+		return NULL;
+	}
+
+	/* NOTE:  if (PIPE_INTERRUPT) { scheduler sets s-mask } */
+
+	/* init as live, toggle clear, advance to dummy */
+	qh->qh_state = QH_STATE_IDLE;
+	hw = qh->hw;
+	hw->hw_info1 = cpu_to_hc32(fotg210, info1);
+	hw->hw_info2 = cpu_to_hc32(fotg210, info2);
+	qh->is_out = !is_input;
+	usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe), !is_input, 1);
+	qh_refresh(fotg210, qh);
+	return qh;
+}
+
+static void enable_async(struct fotg210_hcd *fotg210)
+{
+	if (fotg210->async_count++)
+		return;
+
+	/* Stop waiting to turn off the async schedule */
+	fotg210->enabled_hrtimer_events &= ~BIT(FOTG210_HRTIMER_DISABLE_ASYNC);
+
+	/* Don't start the schedule until ASS is 0 */
+	fotg210_poll_ASS(fotg210);
+	turn_on_io_watchdog(fotg210);
+}
+
+static void disable_async(struct fotg210_hcd *fotg210)
+{
+	if (--fotg210->async_count)
+		return;
+
+	/* The async schedule and async_unlink list are supposed to be empty */
+	WARN_ON(fotg210->async->qh_next.qh || fotg210->async_unlink);
+
+	/* Don't turn off the schedule until ASS is 1 */
+	fotg210_poll_ASS(fotg210);
+}
+
+/* move qh (and its qtds) onto async queue; maybe enable queue.  */
+
+static void qh_link_async(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	__hc32 dma = QH_NEXT(fotg210, qh->qh_dma);
+	struct fotg210_qh *head;
+
+	/* Don't link a QH if there's a Clear-TT-Buffer pending */
+	if (unlikely(qh->clearing_tt))
+		return;
+
+	WARN_ON(qh->qh_state != QH_STATE_IDLE);
+
+	/* clear halt and/or toggle; and maybe recover from silicon quirk */
+	qh_refresh(fotg210, qh);
+
+	/* splice right after start */
+	head = fotg210->async;
+	qh->qh_next = head->qh_next;
+	qh->hw->hw_next = head->hw->hw_next;
+	wmb();
+
+	head->qh_next.qh = qh;
+	head->hw->hw_next = dma;
+
+	qh->xacterrs = 0;
+	qh->qh_state = QH_STATE_LINKED;
+	/* qtd completions reported later by interrupt */
+
+	enable_async(fotg210);
+}
+
+/* For control/bulk/interrupt, return QH with these TDs appended.
+ * Allocates and initializes the QH if necessary.
+ * Returns null if it can't allocate a QH it needs to.
+ * If the QH has TDs (urbs) already, that's great.
+ */
+static struct fotg210_qh *qh_append_tds(struct fotg210_hcd *fotg210,
+		struct urb *urb, struct list_head *qtd_list,
+		int epnum, void **ptr)
+{
+	struct fotg210_qh *qh = NULL;
+	__hc32 qh_addr_mask = cpu_to_hc32(fotg210, 0x7f);
+
+	qh = (struct fotg210_qh *) *ptr;
+	if (unlikely(qh == NULL)) {
+		/* can't sleep here, we have fotg210->lock... */
+		qh = qh_make(fotg210, urb, GFP_ATOMIC);
+		*ptr = qh;
+	}
+	if (likely(qh != NULL)) {
+		struct fotg210_qtd *qtd;
+
+		if (unlikely(list_empty(qtd_list)))
+			qtd = NULL;
+		else
+			qtd = list_entry(qtd_list->next, struct fotg210_qtd,
+					qtd_list);
+
+		/* control qh may need patching ... */
+		if (unlikely(epnum == 0)) {
+			/* usb_reset_device() briefly reverts to address 0 */
+			if (usb_pipedevice(urb->pipe) == 0)
+				qh->hw->hw_info1 &= ~qh_addr_mask;
+		}
+
+		/* just one way to queue requests: swap with the dummy qtd.
+		 * only hc or qh_refresh() ever modify the overlay.
+		 */
+		if (likely(qtd != NULL)) {
+			struct fotg210_qtd *dummy;
+			dma_addr_t dma;
+			__hc32 token;
+
+			/* to avoid racing the HC, use the dummy td instead of
+			 * the first td of our list (becomes new dummy).  both
+			 * tds stay deactivated until we're done, when the
+			 * HC is allowed to fetch the old dummy (4.10.2).
+			 */
+			token = qtd->hw_token;
+			qtd->hw_token = HALT_BIT(fotg210);
+
+			dummy = qh->dummy;
+
+			dma = dummy->qtd_dma;
+			*dummy = *qtd;
+			dummy->qtd_dma = dma;
+
+			list_del(&qtd->qtd_list);
+			list_add(&dummy->qtd_list, qtd_list);
+			list_splice_tail(qtd_list, &qh->qtd_list);
+
+			fotg210_qtd_init(fotg210, qtd, qtd->qtd_dma);
+			qh->dummy = qtd;
+
+			/* hc must see the new dummy at list end */
+			dma = qtd->qtd_dma;
+			qtd = list_entry(qh->qtd_list.prev,
+					struct fotg210_qtd, qtd_list);
+			qtd->hw_next = QTD_NEXT(fotg210, dma);
+
+			/* let the hc process these next qtds */
+			wmb();
+			dummy->hw_token = token;
+
+			urb->hcpriv = qh;
+		}
+	}
+	return qh;
+}
+
+static int submit_async(struct fotg210_hcd *fotg210, struct urb *urb,
+		struct list_head *qtd_list, gfp_t mem_flags)
+{
+	int epnum;
+	unsigned long flags;
+	struct fotg210_qh *qh = NULL;
+	int rc;
+
+	epnum = urb->ep->desc.bEndpointAddress;
+
+#ifdef FOTG210_URB_TRACE
+	{
+		struct fotg210_qtd *qtd;
+
+		qtd = list_entry(qtd_list->next, struct fotg210_qtd, qtd_list);
+		fotg210_dbg(fotg210,
+				"%s %s urb %p ep%d%s len %d, qtd %p [qh %p]\n",
+				__func__, urb->dev->devpath, urb,
+				epnum & 0x0f, (epnum & USB_DIR_IN)
+					? "in" : "out",
+				urb->transfer_buffer_length,
+				qtd, urb->ep->hcpriv);
+	}
+#endif
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+	if (unlikely(!HCD_HW_ACCESSIBLE(fotg210_to_hcd(fotg210)))) {
+		rc = -ESHUTDOWN;
+		goto done;
+	}
+	rc = usb_hcd_link_urb_to_ep(fotg210_to_hcd(fotg210), urb);
+	if (unlikely(rc))
+		goto done;
+
+	qh = qh_append_tds(fotg210, urb, qtd_list, epnum, &urb->ep->hcpriv);
+	if (unlikely(qh == NULL)) {
+		usb_hcd_unlink_urb_from_ep(fotg210_to_hcd(fotg210), urb);
+		rc = -ENOMEM;
+		goto done;
+	}
+
+	/* Control/bulk operations through TTs don't need scheduling,
+	 * the HC and TT handle it when the TT has a buffer ready.
+	 */
+	if (likely(qh->qh_state == QH_STATE_IDLE))
+		qh_link_async(fotg210, qh);
+done:
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	if (unlikely(qh == NULL))
+		qtd_list_free(fotg210, urb, qtd_list);
+	return rc;
+}
+
+static void single_unlink_async(struct fotg210_hcd *fotg210,
+		struct fotg210_qh *qh)
+{
+	struct fotg210_qh *prev;
+
+	/* Add to the end of the list of QHs waiting for the next IAAD */
+	qh->qh_state = QH_STATE_UNLINK;
+	if (fotg210->async_unlink)
+		fotg210->async_unlink_last->unlink_next = qh;
+	else
+		fotg210->async_unlink = qh;
+	fotg210->async_unlink_last = qh;
+
+	/* Unlink it from the schedule */
+	prev = fotg210->async;
+	while (prev->qh_next.qh != qh)
+		prev = prev->qh_next.qh;
+
+	prev->hw->hw_next = qh->hw->hw_next;
+	prev->qh_next = qh->qh_next;
+	if (fotg210->qh_scan_next == qh)
+		fotg210->qh_scan_next = qh->qh_next.qh;
+}
+
+static void start_iaa_cycle(struct fotg210_hcd *fotg210, bool nested)
+{
+	/*
+	 * Do nothing if an IAA cycle is already running or
+	 * if one will be started shortly.
+	 */
+	if (fotg210->async_iaa || fotg210->async_unlinking)
+		return;
+
+	/* Do all the waiting QHs at once */
+	fotg210->async_iaa = fotg210->async_unlink;
+	fotg210->async_unlink = NULL;
+
+	/* If the controller isn't running, we don't have to wait for it */
+	if (unlikely(fotg210->rh_state < FOTG210_RH_RUNNING)) {
+		if (!nested)		/* Avoid recursion */
+			end_unlink_async(fotg210);
+
+	/* Otherwise start a new IAA cycle */
+	} else if (likely(fotg210->rh_state == FOTG210_RH_RUNNING)) {
+		/* Make sure the unlinks are all visible to the hardware */
+		wmb();
+
+		fotg210_writel(fotg210, fotg210->command | CMD_IAAD,
+				&fotg210->regs->command);
+		fotg210_readl(fotg210, &fotg210->regs->command);
+		fotg210_enable_event(fotg210, FOTG210_HRTIMER_IAA_WATCHDOG,
+				true);
+	}
+}
+
+/* the async qh for the qtds being unlinked are now gone from the HC */
+
+static void end_unlink_async(struct fotg210_hcd *fotg210)
+{
+	struct fotg210_qh *qh;
+
+	/* Process the idle QHs */
+restart:
+	fotg210->async_unlinking = true;
+	while (fotg210->async_iaa) {
+		qh = fotg210->async_iaa;
+		fotg210->async_iaa = qh->unlink_next;
+		qh->unlink_next = NULL;
+
+		qh->qh_state = QH_STATE_IDLE;
+		qh->qh_next.qh = NULL;
+
+		qh_completions(fotg210, qh);
+		if (!list_empty(&qh->qtd_list) &&
+				fotg210->rh_state == FOTG210_RH_RUNNING)
+			qh_link_async(fotg210, qh);
+		disable_async(fotg210);
+	}
+	fotg210->async_unlinking = false;
+
+	/* Start a new IAA cycle if any QHs are waiting for it */
+	if (fotg210->async_unlink) {
+		start_iaa_cycle(fotg210, true);
+		if (unlikely(fotg210->rh_state < FOTG210_RH_RUNNING))
+			goto restart;
+	}
+}
+
+static void unlink_empty_async(struct fotg210_hcd *fotg210)
+{
+	struct fotg210_qh *qh, *next;
+	bool stopped = (fotg210->rh_state < FOTG210_RH_RUNNING);
+	bool check_unlinks_later = false;
+
+	/* Unlink all the async QHs that have been empty for a timer cycle */
+	next = fotg210->async->qh_next.qh;
+	while (next) {
+		qh = next;
+		next = qh->qh_next.qh;
+
+		if (list_empty(&qh->qtd_list) &&
+				qh->qh_state == QH_STATE_LINKED) {
+			if (!stopped && qh->unlink_cycle ==
+					fotg210->async_unlink_cycle)
+				check_unlinks_later = true;
+			else
+				single_unlink_async(fotg210, qh);
+		}
+	}
+
+	/* Start a new IAA cycle if any QHs are waiting for it */
+	if (fotg210->async_unlink)
+		start_iaa_cycle(fotg210, false);
+
+	/* QHs that haven't been empty for long enough will be handled later */
+	if (check_unlinks_later) {
+		fotg210_enable_event(fotg210, FOTG210_HRTIMER_ASYNC_UNLINKS,
+				true);
+		++fotg210->async_unlink_cycle;
+	}
+}
+
+/* makes sure the async qh will become idle */
+/* caller must own fotg210->lock */
+
+static void start_unlink_async(struct fotg210_hcd *fotg210,
+		struct fotg210_qh *qh)
+{
+	/*
+	 * If the QH isn't linked then there's nothing we can do
+	 * unless we were called during a giveback, in which case
+	 * qh_completions() has to deal with it.
+	 */
+	if (qh->qh_state != QH_STATE_LINKED) {
+		if (qh->qh_state == QH_STATE_COMPLETING)
+			qh->needs_rescan = 1;
+		return;
+	}
+
+	single_unlink_async(fotg210, qh);
+	start_iaa_cycle(fotg210, false);
+}
+
+static void scan_async(struct fotg210_hcd *fotg210)
+{
+	struct fotg210_qh *qh;
+	bool check_unlinks_later = false;
+
+	fotg210->qh_scan_next = fotg210->async->qh_next.qh;
+	while (fotg210->qh_scan_next) {
+		qh = fotg210->qh_scan_next;
+		fotg210->qh_scan_next = qh->qh_next.qh;
+rescan:
+		/* clean any finished work for this qh */
+		if (!list_empty(&qh->qtd_list)) {
+			int temp;
+
+			/*
+			 * Unlinks could happen here; completion reporting
+			 * drops the lock.  That's why fotg210->qh_scan_next
+			 * always holds the next qh to scan; if the next qh
+			 * gets unlinked then fotg210->qh_scan_next is adjusted
+			 * in single_unlink_async().
+			 */
+			temp = qh_completions(fotg210, qh);
+			if (qh->needs_rescan) {
+				start_unlink_async(fotg210, qh);
+			} else if (list_empty(&qh->qtd_list)
+					&& qh->qh_state == QH_STATE_LINKED) {
+				qh->unlink_cycle = fotg210->async_unlink_cycle;
+				check_unlinks_later = true;
+			} else if (temp != 0)
+				goto rescan;
+		}
+	}
+
+	/*
+	 * Unlink empty entries, reducing DMA usage as well
+	 * as HCD schedule-scanning costs.  Delay for any qh
+	 * we just scanned, there's a not-unusual case that it
+	 * doesn't stay idle for long.
+	 */
+	if (check_unlinks_later && fotg210->rh_state == FOTG210_RH_RUNNING &&
+			!(fotg210->enabled_hrtimer_events &
+			BIT(FOTG210_HRTIMER_ASYNC_UNLINKS))) {
+		fotg210_enable_event(fotg210,
+				FOTG210_HRTIMER_ASYNC_UNLINKS, true);
+		++fotg210->async_unlink_cycle;
+	}
+}
+/* EHCI scheduled transaction support:  interrupt, iso, split iso
+ * These are called "periodic" transactions in the EHCI spec.
+ *
+ * Note that for interrupt transfers, the QH/QTD manipulation is shared
+ * with the "asynchronous" transaction support (control/bulk transfers).
+ * The only real difference is in how interrupt transfers are scheduled.
+ *
+ * For ISO, we make an "iso_stream" head to serve the same role as a QH.
+ * It keeps track of every ITD (or SITD) that's linked, and holds enough
+ * pre-calculated schedule data to make appending to the queue be quick.
+ */
+static int fotg210_get_frame(struct usb_hcd *hcd);
+
+/* periodic_next_shadow - return "next" pointer on shadow list
+ * @periodic: host pointer to qh/itd
+ * @tag: hardware tag for type of this record
+ */
+static union fotg210_shadow *periodic_next_shadow(struct fotg210_hcd *fotg210,
+		union fotg210_shadow *periodic, __hc32 tag)
+{
+	switch (hc32_to_cpu(fotg210, tag)) {
+	case Q_TYPE_QH:
+		return &periodic->qh->qh_next;
+	case Q_TYPE_FSTN:
+		return &periodic->fstn->fstn_next;
+	default:
+		return &periodic->itd->itd_next;
+	}
+}
+
+static __hc32 *shadow_next_periodic(struct fotg210_hcd *fotg210,
+		union fotg210_shadow *periodic, __hc32 tag)
+{
+	switch (hc32_to_cpu(fotg210, tag)) {
+	/* our fotg210_shadow.qh is actually software part */
+	case Q_TYPE_QH:
+		return &periodic->qh->hw->hw_next;
+	/* others are hw parts */
+	default:
+		return periodic->hw_next;
+	}
+}
+
+/* caller must hold fotg210->lock */
+static void periodic_unlink(struct fotg210_hcd *fotg210, unsigned frame,
+		void *ptr)
+{
+	union fotg210_shadow *prev_p = &fotg210->pshadow[frame];
+	__hc32 *hw_p = &fotg210->periodic[frame];
+	union fotg210_shadow here = *prev_p;
+
+	/* find predecessor of "ptr"; hw and shadow lists are in sync */
+	while (here.ptr && here.ptr != ptr) {
+		prev_p = periodic_next_shadow(fotg210, prev_p,
+				Q_NEXT_TYPE(fotg210, *hw_p));
+		hw_p = shadow_next_periodic(fotg210, &here,
+				Q_NEXT_TYPE(fotg210, *hw_p));
+		here = *prev_p;
+	}
+	/* an interrupt entry (at list end) could have been shared */
+	if (!here.ptr)
+		return;
+
+	/* update shadow and hardware lists ... the old "next" pointers
+	 * from ptr may still be in use, the caller updates them.
+	 */
+	*prev_p = *periodic_next_shadow(fotg210, &here,
+			Q_NEXT_TYPE(fotg210, *hw_p));
+
+	*hw_p = *shadow_next_periodic(fotg210, &here,
+			Q_NEXT_TYPE(fotg210, *hw_p));
+}
+
+/* how many of the uframe's 125 usecs are allocated? */
+static unsigned short periodic_usecs(struct fotg210_hcd *fotg210,
+		unsigned frame, unsigned uframe)
+{
+	__hc32 *hw_p = &fotg210->periodic[frame];
+	union fotg210_shadow *q = &fotg210->pshadow[frame];
+	unsigned usecs = 0;
+	struct fotg210_qh_hw *hw;
+
+	while (q->ptr) {
+		switch (hc32_to_cpu(fotg210, Q_NEXT_TYPE(fotg210, *hw_p))) {
+		case Q_TYPE_QH:
+			hw = q->qh->hw;
+			/* is it in the S-mask? */
+			if (hw->hw_info2 & cpu_to_hc32(fotg210, 1 << uframe))
+				usecs += q->qh->usecs;
+			/* ... or C-mask? */
+			if (hw->hw_info2 & cpu_to_hc32(fotg210,
+					1 << (8 + uframe)))
+				usecs += q->qh->c_usecs;
+			hw_p = &hw->hw_next;
+			q = &q->qh->qh_next;
+			break;
+		/* case Q_TYPE_FSTN: */
+		default:
+			/* for "save place" FSTNs, count the relevant INTR
+			 * bandwidth from the previous frame
+			 */
+			if (q->fstn->hw_prev != FOTG210_LIST_END(fotg210))
+				fotg210_dbg(fotg210, "ignoring FSTN cost ...\n");
+
+			hw_p = &q->fstn->hw_next;
+			q = &q->fstn->fstn_next;
+			break;
+		case Q_TYPE_ITD:
+			if (q->itd->hw_transaction[uframe])
+				usecs += q->itd->stream->usecs;
+			hw_p = &q->itd->hw_next;
+			q = &q->itd->itd_next;
+			break;
+		}
+	}
+	if (usecs > fotg210->uframe_periodic_max)
+		fotg210_err(fotg210, "uframe %d sched overrun: %d usecs\n",
+				frame * 8 + uframe, usecs);
+	return usecs;
+}
+
+static int same_tt(struct usb_device *dev1, struct usb_device *dev2)
+{
+	if (!dev1->tt || !dev2->tt)
+		return 0;
+	if (dev1->tt != dev2->tt)
+		return 0;
+	if (dev1->tt->multi)
+		return dev1->ttport == dev2->ttport;
+	else
+		return 1;
+}
+
+/* return true iff the device's transaction translator is available
+ * for a periodic transfer starting at the specified frame, using
+ * all the uframes in the mask.
+ */
+static int tt_no_collision(struct fotg210_hcd *fotg210, unsigned period,
+		struct usb_device *dev, unsigned frame, u32 uf_mask)
+{
+	if (period == 0)	/* error */
+		return 0;
+
+	/* note bandwidth wastage:  split never follows csplit
+	 * (different dev or endpoint) until the next uframe.
+	 * calling convention doesn't make that distinction.
+	 */
+	for (; frame < fotg210->periodic_size; frame += period) {
+		union fotg210_shadow here;
+		__hc32 type;
+		struct fotg210_qh_hw *hw;
+
+		here = fotg210->pshadow[frame];
+		type = Q_NEXT_TYPE(fotg210, fotg210->periodic[frame]);
+		while (here.ptr) {
+			switch (hc32_to_cpu(fotg210, type)) {
+			case Q_TYPE_ITD:
+				type = Q_NEXT_TYPE(fotg210, here.itd->hw_next);
+				here = here.itd->itd_next;
+				continue;
+			case Q_TYPE_QH:
+				hw = here.qh->hw;
+				if (same_tt(dev, here.qh->dev)) {
+					u32 mask;
+
+					mask = hc32_to_cpu(fotg210,
+							hw->hw_info2);
+					/* "knows" no gap is needed */
+					mask |= mask >> 8;
+					if (mask & uf_mask)
+						break;
+				}
+				type = Q_NEXT_TYPE(fotg210, hw->hw_next);
+				here = here.qh->qh_next;
+				continue;
+			/* case Q_TYPE_FSTN: */
+			default:
+				fotg210_dbg(fotg210,
+						"periodic frame %d bogus type %d\n",
+						frame, type);
+			}
+
+			/* collision or error */
+			return 0;
+		}
+	}
+
+	/* no collision */
+	return 1;
+}
+
+static void enable_periodic(struct fotg210_hcd *fotg210)
+{
+	if (fotg210->periodic_count++)
+		return;
+
+	/* Stop waiting to turn off the periodic schedule */
+	fotg210->enabled_hrtimer_events &=
+		~BIT(FOTG210_HRTIMER_DISABLE_PERIODIC);
+
+	/* Don't start the schedule until PSS is 0 */
+	fotg210_poll_PSS(fotg210);
+	turn_on_io_watchdog(fotg210);
+}
+
+static void disable_periodic(struct fotg210_hcd *fotg210)
+{
+	if (--fotg210->periodic_count)
+		return;
+
+	/* Don't turn off the schedule until PSS is 1 */
+	fotg210_poll_PSS(fotg210);
+}
+
+/* periodic schedule slots have iso tds (normal or split) first, then a
+ * sparse tree for active interrupt transfers.
+ *
+ * this just links in a qh; caller guarantees uframe masks are set right.
+ * no FSTN support (yet; fotg210 0.96+)
+ */
+static void qh_link_periodic(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	unsigned i;
+	unsigned period = qh->period;
+
+	dev_dbg(&qh->dev->dev,
+			"link qh%d-%04x/%p start %d [%d/%d us]\n", period,
+			hc32_to_cpup(fotg210, &qh->hw->hw_info2) &
+			(QH_CMASK | QH_SMASK), qh, qh->start, qh->usecs,
+			qh->c_usecs);
+
+	/* high bandwidth, or otherwise every microframe */
+	if (period == 0)
+		period = 1;
+
+	for (i = qh->start; i < fotg210->periodic_size; i += period) {
+		union fotg210_shadow *prev = &fotg210->pshadow[i];
+		__hc32 *hw_p = &fotg210->periodic[i];
+		union fotg210_shadow here = *prev;
+		__hc32 type = 0;
+
+		/* skip the iso nodes at list head */
+		while (here.ptr) {
+			type = Q_NEXT_TYPE(fotg210, *hw_p);
+			if (type == cpu_to_hc32(fotg210, Q_TYPE_QH))
+				break;
+			prev = periodic_next_shadow(fotg210, prev, type);
+			hw_p = shadow_next_periodic(fotg210, &here, type);
+			here = *prev;
+		}
+
+		/* sorting each branch by period (slow-->fast)
+		 * enables sharing interior tree nodes
+		 */
+		while (here.ptr && qh != here.qh) {
+			if (qh->period > here.qh->period)
+				break;
+			prev = &here.qh->qh_next;
+			hw_p = &here.qh->hw->hw_next;
+			here = *prev;
+		}
+		/* link in this qh, unless some earlier pass did that */
+		if (qh != here.qh) {
+			qh->qh_next = here;
+			if (here.qh)
+				qh->hw->hw_next = *hw_p;
+			wmb();
+			prev->qh = qh;
+			*hw_p = QH_NEXT(fotg210, qh->qh_dma);
+		}
+	}
+	qh->qh_state = QH_STATE_LINKED;
+	qh->xacterrs = 0;
+
+	/* update per-qh bandwidth for usbfs */
+	fotg210_to_hcd(fotg210)->self.bandwidth_allocated += qh->period
+		? ((qh->usecs + qh->c_usecs) / qh->period)
+		: (qh->usecs * 8);
+
+	list_add(&qh->intr_node, &fotg210->intr_qh_list);
+
+	/* maybe enable periodic schedule processing */
+	++fotg210->intr_count;
+	enable_periodic(fotg210);
+}
+
+static void qh_unlink_periodic(struct fotg210_hcd *fotg210,
+		struct fotg210_qh *qh)
+{
+	unsigned i;
+	unsigned period;
+
+	/*
+	 * If qh is for a low/full-speed device, simply unlinking it
+	 * could interfere with an ongoing split transaction.  To unlink
+	 * it safely would require setting the QH_INACTIVATE bit and
+	 * waiting at least one frame, as described in EHCI 4.12.2.5.
+	 *
+	 * We won't bother with any of this.  Instead, we assume that the
+	 * only reason for unlinking an interrupt QH while the current URB
+	 * is still active is to dequeue all the URBs (flush the whole
+	 * endpoint queue).
+	 *
+	 * If rebalancing the periodic schedule is ever implemented, this
+	 * approach will no longer be valid.
+	 */
+
+	/* high bandwidth, or otherwise part of every microframe */
+	period = qh->period;
+	if (!period)
+		period = 1;
+
+	for (i = qh->start; i < fotg210->periodic_size; i += period)
+		periodic_unlink(fotg210, i, qh);
+
+	/* update per-qh bandwidth for usbfs */
+	fotg210_to_hcd(fotg210)->self.bandwidth_allocated -= qh->period
+		? ((qh->usecs + qh->c_usecs) / qh->period)
+		: (qh->usecs * 8);
+
+	dev_dbg(&qh->dev->dev,
+			"unlink qh%d-%04x/%p start %d [%d/%d us]\n",
+			qh->period, hc32_to_cpup(fotg210, &qh->hw->hw_info2) &
+			(QH_CMASK | QH_SMASK), qh, qh->start, qh->usecs,
+			qh->c_usecs);
+
+	/* qh->qh_next still "live" to HC */
+	qh->qh_state = QH_STATE_UNLINK;
+	qh->qh_next.ptr = NULL;
+
+	if (fotg210->qh_scan_next == qh)
+		fotg210->qh_scan_next = list_entry(qh->intr_node.next,
+				struct fotg210_qh, intr_node);
+	list_del(&qh->intr_node);
+}
+
+static void start_unlink_intr(struct fotg210_hcd *fotg210,
+		struct fotg210_qh *qh)
+{
+	/* If the QH isn't linked then there's nothing we can do
+	 * unless we were called during a giveback, in which case
+	 * qh_completions() has to deal with it.
+	 */
+	if (qh->qh_state != QH_STATE_LINKED) {
+		if (qh->qh_state == QH_STATE_COMPLETING)
+			qh->needs_rescan = 1;
+		return;
+	}
+
+	qh_unlink_periodic(fotg210, qh);
+
+	/* Make sure the unlinks are visible before starting the timer */
+	wmb();
+
+	/*
+	 * The EHCI spec doesn't say how long it takes the controller to
+	 * stop accessing an unlinked interrupt QH.  The timer delay is
+	 * 9 uframes; presumably that will be long enough.
+	 */
+	qh->unlink_cycle = fotg210->intr_unlink_cycle;
+
+	/* New entries go at the end of the intr_unlink list */
+	if (fotg210->intr_unlink)
+		fotg210->intr_unlink_last->unlink_next = qh;
+	else
+		fotg210->intr_unlink = qh;
+	fotg210->intr_unlink_last = qh;
+
+	if (fotg210->intr_unlinking)
+		;	/* Avoid recursive calls */
+	else if (fotg210->rh_state < FOTG210_RH_RUNNING)
+		fotg210_handle_intr_unlinks(fotg210);
+	else if (fotg210->intr_unlink == qh) {
+		fotg210_enable_event(fotg210, FOTG210_HRTIMER_UNLINK_INTR,
+				true);
+		++fotg210->intr_unlink_cycle;
+	}
+}
+
+static void end_unlink_intr(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	struct fotg210_qh_hw *hw = qh->hw;
+	int rc;
+
+	qh->qh_state = QH_STATE_IDLE;
+	hw->hw_next = FOTG210_LIST_END(fotg210);
+
+	qh_completions(fotg210, qh);
+
+	/* reschedule QH iff another request is queued */
+	if (!list_empty(&qh->qtd_list) &&
+			fotg210->rh_state == FOTG210_RH_RUNNING) {
+		rc = qh_schedule(fotg210, qh);
+
+		/* An error here likely indicates handshake failure
+		 * or no space left in the schedule.  Neither fault
+		 * should happen often ...
+		 *
+		 * FIXME kill the now-dysfunctional queued urbs
+		 */
+		if (rc != 0)
+			fotg210_err(fotg210, "can't reschedule qh %p, err %d\n",
+					qh, rc);
+	}
+
+	/* maybe turn off periodic schedule */
+	--fotg210->intr_count;
+	disable_periodic(fotg210);
+}
+
+static int check_period(struct fotg210_hcd *fotg210, unsigned frame,
+		unsigned uframe, unsigned period, unsigned usecs)
+{
+	int claimed;
+
+	/* complete split running into next frame?
+	 * given FSTN support, we could sometimes check...
+	 */
+	if (uframe >= 8)
+		return 0;
+
+	/* convert "usecs we need" to "max already claimed" */
+	usecs = fotg210->uframe_periodic_max - usecs;
+
+	/* we "know" 2 and 4 uframe intervals were rejected; so
+	 * for period 0, check _every_ microframe in the schedule.
+	 */
+	if (unlikely(period == 0)) {
+		do {
+			for (uframe = 0; uframe < 7; uframe++) {
+				claimed = periodic_usecs(fotg210, frame,
+						uframe);
+				if (claimed > usecs)
+					return 0;
+			}
+		} while ((frame += 1) < fotg210->periodic_size);
+
+	/* just check the specified uframe, at that period */
+	} else {
+		do {
+			claimed = periodic_usecs(fotg210, frame, uframe);
+			if (claimed > usecs)
+				return 0;
+		} while ((frame += period) < fotg210->periodic_size);
+	}
+
+	/* success! */
+	return 1;
+}
+
+static int check_intr_schedule(struct fotg210_hcd *fotg210, unsigned frame,
+		unsigned uframe, const struct fotg210_qh *qh, __hc32 *c_maskp)
+{
+	int retval = -ENOSPC;
+	u8 mask = 0;
+
+	if (qh->c_usecs && uframe >= 6)		/* FSTN territory? */
+		goto done;
+
+	if (!check_period(fotg210, frame, uframe, qh->period, qh->usecs))
+		goto done;
+	if (!qh->c_usecs) {
+		retval = 0;
+		*c_maskp = 0;
+		goto done;
+	}
+
+	/* Make sure this tt's buffer is also available for CSPLITs.
+	 * We pessimize a bit; probably the typical full speed case
+	 * doesn't need the second CSPLIT.
+	 *
+	 * NOTE:  both SPLIT and CSPLIT could be checked in just
+	 * one smart pass...
+	 */
+	mask = 0x03 << (uframe + qh->gap_uf);
+	*c_maskp = cpu_to_hc32(fotg210, mask << 8);
+
+	mask |= 1 << uframe;
+	if (tt_no_collision(fotg210, qh->period, qh->dev, frame, mask)) {
+		if (!check_period(fotg210, frame, uframe + qh->gap_uf + 1,
+				qh->period, qh->c_usecs))
+			goto done;
+		if (!check_period(fotg210, frame, uframe + qh->gap_uf,
+				qh->period, qh->c_usecs))
+			goto done;
+		retval = 0;
+	}
+done:
+	return retval;
+}
+
+/* "first fit" scheduling policy used the first time through,
+ * or when the previous schedule slot can't be re-used.
+ */
+static int qh_schedule(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	int status;
+	unsigned uframe;
+	__hc32 c_mask;
+	unsigned frame;	/* 0..(qh->period - 1), or NO_FRAME */
+	struct fotg210_qh_hw *hw = qh->hw;
+
+	qh_refresh(fotg210, qh);
+	hw->hw_next = FOTG210_LIST_END(fotg210);
+	frame = qh->start;
+
+	/* reuse the previous schedule slots, if we can */
+	if (frame < qh->period) {
+		uframe = ffs(hc32_to_cpup(fotg210, &hw->hw_info2) & QH_SMASK);
+		status = check_intr_schedule(fotg210, frame, --uframe,
+				qh, &c_mask);
+	} else {
+		uframe = 0;
+		c_mask = 0;
+		status = -ENOSPC;
+	}
+
+	/* else scan the schedule to find a group of slots such that all
+	 * uframes have enough periodic bandwidth available.
+	 */
+	if (status) {
+		/* "normal" case, uframing flexible except with splits */
+		if (qh->period) {
+			int i;
+
+			for (i = qh->period; status && i > 0; --i) {
+				frame = ++fotg210->random_frame % qh->period;
+				for (uframe = 0; uframe < 8; uframe++) {
+					status = check_intr_schedule(fotg210,
+							frame, uframe, qh,
+							&c_mask);
+					if (status == 0)
+						break;
+				}
+			}
+
+		/* qh->period == 0 means every uframe */
+		} else {
+			frame = 0;
+			status = check_intr_schedule(fotg210, 0, 0, qh,
+					&c_mask);
+		}
+		if (status)
+			goto done;
+		qh->start = frame;
+
+		/* reset S-frame and (maybe) C-frame masks */
+		hw->hw_info2 &= cpu_to_hc32(fotg210, ~(QH_CMASK | QH_SMASK));
+		hw->hw_info2 |= qh->period
+			? cpu_to_hc32(fotg210, 1 << uframe)
+			: cpu_to_hc32(fotg210, QH_SMASK);
+		hw->hw_info2 |= c_mask;
+	} else
+		fotg210_dbg(fotg210, "reused qh %p schedule\n", qh);
+
+	/* stuff into the periodic schedule */
+	qh_link_periodic(fotg210, qh);
+done:
+	return status;
+}
+
+static int intr_submit(struct fotg210_hcd *fotg210, struct urb *urb,
+		struct list_head *qtd_list, gfp_t mem_flags)
+{
+	unsigned epnum;
+	unsigned long flags;
+	struct fotg210_qh *qh;
+	int status;
+	struct list_head empty;
+
+	/* get endpoint and transfer/schedule data */
+	epnum = urb->ep->desc.bEndpointAddress;
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+
+	if (unlikely(!HCD_HW_ACCESSIBLE(fotg210_to_hcd(fotg210)))) {
+		status = -ESHUTDOWN;
+		goto done_not_linked;
+	}
+	status = usb_hcd_link_urb_to_ep(fotg210_to_hcd(fotg210), urb);
+	if (unlikely(status))
+		goto done_not_linked;
+
+	/* get qh and force any scheduling errors */
+	INIT_LIST_HEAD(&empty);
+	qh = qh_append_tds(fotg210, urb, &empty, epnum, &urb->ep->hcpriv);
+	if (qh == NULL) {
+		status = -ENOMEM;
+		goto done;
+	}
+	if (qh->qh_state == QH_STATE_IDLE) {
+		status = qh_schedule(fotg210, qh);
+		if (status)
+			goto done;
+	}
+
+	/* then queue the urb's tds to the qh */
+	qh = qh_append_tds(fotg210, urb, qtd_list, epnum, &urb->ep->hcpriv);
+	BUG_ON(qh == NULL);
+
+	/* ... update usbfs periodic stats */
+	fotg210_to_hcd(fotg210)->self.bandwidth_int_reqs++;
+
+done:
+	if (unlikely(status))
+		usb_hcd_unlink_urb_from_ep(fotg210_to_hcd(fotg210), urb);
+done_not_linked:
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	if (status)
+		qtd_list_free(fotg210, urb, qtd_list);
+
+	return status;
+}
+
+static void scan_intr(struct fotg210_hcd *fotg210)
+{
+	struct fotg210_qh *qh;
+
+	list_for_each_entry_safe(qh, fotg210->qh_scan_next,
+			&fotg210->intr_qh_list, intr_node) {
+rescan:
+		/* clean any finished work for this qh */
+		if (!list_empty(&qh->qtd_list)) {
+			int temp;
+
+			/*
+			 * Unlinks could happen here; completion reporting
+			 * drops the lock.  That's why fotg210->qh_scan_next
+			 * always holds the next qh to scan; if the next qh
+			 * gets unlinked then fotg210->qh_scan_next is adjusted
+			 * in qh_unlink_periodic().
+			 */
+			temp = qh_completions(fotg210, qh);
+			if (unlikely(qh->needs_rescan ||
+					(list_empty(&qh->qtd_list) &&
+					qh->qh_state == QH_STATE_LINKED)))
+				start_unlink_intr(fotg210, qh);
+			else if (temp != 0)
+				goto rescan;
+		}
+	}
+}
+
+/* fotg210_iso_stream ops work with both ITD and SITD */
+
+static struct fotg210_iso_stream *iso_stream_alloc(gfp_t mem_flags)
+{
+	struct fotg210_iso_stream *stream;
+
+	stream = kzalloc(sizeof(*stream), mem_flags);
+	if (likely(stream != NULL)) {
+		INIT_LIST_HEAD(&stream->td_list);
+		INIT_LIST_HEAD(&stream->free_list);
+		stream->next_uframe = -1;
+	}
+	return stream;
+}
+
+static void iso_stream_init(struct fotg210_hcd *fotg210,
+		struct fotg210_iso_stream *stream, struct usb_device *dev,
+		int pipe, unsigned interval)
+{
+	u32 buf1;
+	unsigned epnum, maxp;
+	int is_input;
+	long bandwidth;
+	unsigned multi;
+	struct usb_host_endpoint *ep;
+
+	/*
+	 * this might be a "high bandwidth" highspeed endpoint,
+	 * as encoded in the ep descriptor's wMaxPacket field
+	 */
+	epnum = usb_pipeendpoint(pipe);
+	is_input = usb_pipein(pipe) ? USB_DIR_IN : 0;
+	ep = usb_pipe_endpoint(dev, pipe);
+	maxp = usb_endpoint_maxp(&ep->desc);
+	if (is_input)
+		buf1 = (1 << 11);
+	else
+		buf1 = 0;
+
+	multi = usb_endpoint_maxp_mult(&ep->desc);
+	buf1 |= maxp;
+	maxp *= multi;
+
+	stream->buf0 = cpu_to_hc32(fotg210, (epnum << 8) | dev->devnum);
+	stream->buf1 = cpu_to_hc32(fotg210, buf1);
+	stream->buf2 = cpu_to_hc32(fotg210, multi);
+
+	/* usbfs wants to report the average usecs per frame tied up
+	 * when transfers on this endpoint are scheduled ...
+	 */
+	if (dev->speed == USB_SPEED_FULL) {
+		interval <<= 3;
+		stream->usecs = NS_TO_US(usb_calc_bus_time(dev->speed,
+				is_input, 1, maxp));
+		stream->usecs /= 8;
+	} else {
+		stream->highspeed = 1;
+		stream->usecs = HS_USECS_ISO(maxp);
+	}
+	bandwidth = stream->usecs * 8;
+	bandwidth /= interval;
+
+	stream->bandwidth = bandwidth;
+	stream->udev = dev;
+	stream->bEndpointAddress = is_input | epnum;
+	stream->interval = interval;
+	stream->maxp = maxp;
+}
+
+static struct fotg210_iso_stream *iso_stream_find(struct fotg210_hcd *fotg210,
+		struct urb *urb)
+{
+	unsigned epnum;
+	struct fotg210_iso_stream *stream;
+	struct usb_host_endpoint *ep;
+	unsigned long flags;
+
+	epnum = usb_pipeendpoint(urb->pipe);
+	if (usb_pipein(urb->pipe))
+		ep = urb->dev->ep_in[epnum];
+	else
+		ep = urb->dev->ep_out[epnum];
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+	stream = ep->hcpriv;
+
+	if (unlikely(stream == NULL)) {
+		stream = iso_stream_alloc(GFP_ATOMIC);
+		if (likely(stream != NULL)) {
+			ep->hcpriv = stream;
+			stream->ep = ep;
+			iso_stream_init(fotg210, stream, urb->dev, urb->pipe,
+					urb->interval);
+		}
+
+	/* if dev->ep[epnum] is a QH, hw is set */
+	} else if (unlikely(stream->hw != NULL)) {
+		fotg210_dbg(fotg210, "dev %s ep%d%s, not iso??\n",
+				urb->dev->devpath, epnum,
+				usb_pipein(urb->pipe) ? "in" : "out");
+		stream = NULL;
+	}
+
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	return stream;
+}
+
+/* fotg210_iso_sched ops can be ITD-only or SITD-only */
+
+static struct fotg210_iso_sched *iso_sched_alloc(unsigned packets,
+		gfp_t mem_flags)
+{
+	struct fotg210_iso_sched *iso_sched;
+
+	iso_sched = kzalloc(struct_size(iso_sched, packet, packets), mem_flags);
+	if (likely(iso_sched != NULL))
+		INIT_LIST_HEAD(&iso_sched->td_list);
+
+	return iso_sched;
+}
+
+static inline void itd_sched_init(struct fotg210_hcd *fotg210,
+		struct fotg210_iso_sched *iso_sched,
+		struct fotg210_iso_stream *stream, struct urb *urb)
+{
+	unsigned i;
+	dma_addr_t dma = urb->transfer_dma;
+
+	/* how many uframes are needed for these transfers */
+	iso_sched->span = urb->number_of_packets * stream->interval;
+
+	/* figure out per-uframe itd fields that we'll need later
+	 * when we fit new itds into the schedule.
+	 */
+	for (i = 0; i < urb->number_of_packets; i++) {
+		struct fotg210_iso_packet *uframe = &iso_sched->packet[i];
+		unsigned length;
+		dma_addr_t buf;
+		u32 trans;
+
+		length = urb->iso_frame_desc[i].length;
+		buf = dma + urb->iso_frame_desc[i].offset;
+
+		trans = FOTG210_ISOC_ACTIVE;
+		trans |= buf & 0x0fff;
+		if (unlikely(((i + 1) == urb->number_of_packets))
+				&& !(urb->transfer_flags & URB_NO_INTERRUPT))
+			trans |= FOTG210_ITD_IOC;
+		trans |= length << 16;
+		uframe->transaction = cpu_to_hc32(fotg210, trans);
+
+		/* might need to cross a buffer page within a uframe */
+		uframe->bufp = (buf & ~(u64)0x0fff);
+		buf += length;
+		if (unlikely((uframe->bufp != (buf & ~(u64)0x0fff))))
+			uframe->cross = 1;
+	}
+}
+
+static void iso_sched_free(struct fotg210_iso_stream *stream,
+		struct fotg210_iso_sched *iso_sched)
+{
+	if (!iso_sched)
+		return;
+	/* caller must hold fotg210->lock!*/
+	list_splice(&iso_sched->td_list, &stream->free_list);
+	kfree(iso_sched);
+}
+
+static int itd_urb_transaction(struct fotg210_iso_stream *stream,
+		struct fotg210_hcd *fotg210, struct urb *urb, gfp_t mem_flags)
+{
+	struct fotg210_itd *itd;
+	dma_addr_t itd_dma;
+	int i;
+	unsigned num_itds;
+	struct fotg210_iso_sched *sched;
+	unsigned long flags;
+
+	sched = iso_sched_alloc(urb->number_of_packets, mem_flags);
+	if (unlikely(sched == NULL))
+		return -ENOMEM;
+
+	itd_sched_init(fotg210, sched, stream, urb);
+
+	if (urb->interval < 8)
+		num_itds = 1 + (sched->span + 7) / 8;
+	else
+		num_itds = urb->number_of_packets;
+
+	/* allocate/init ITDs */
+	spin_lock_irqsave(&fotg210->lock, flags);
+	for (i = 0; i < num_itds; i++) {
+
+		/*
+		 * Use iTDs from the free list, but not iTDs that may
+		 * still be in use by the hardware.
+		 */
+		if (likely(!list_empty(&stream->free_list))) {
+			itd = list_first_entry(&stream->free_list,
+					struct fotg210_itd, itd_list);
+			if (itd->frame == fotg210->now_frame)
+				goto alloc_itd;
+			list_del(&itd->itd_list);
+			itd_dma = itd->itd_dma;
+		} else {
+alloc_itd:
+			spin_unlock_irqrestore(&fotg210->lock, flags);
+			itd = dma_pool_alloc(fotg210->itd_pool, mem_flags,
+					&itd_dma);
+			spin_lock_irqsave(&fotg210->lock, flags);
+			if (!itd) {
+				iso_sched_free(stream, sched);
+				spin_unlock_irqrestore(&fotg210->lock, flags);
+				return -ENOMEM;
+			}
+		}
+
+		memset(itd, 0, sizeof(*itd));
+		itd->itd_dma = itd_dma;
+		list_add(&itd->itd_list, &sched->td_list);
+	}
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+
+	/* temporarily store schedule info in hcpriv */
+	urb->hcpriv = sched;
+	urb->error_count = 0;
+	return 0;
+}
+
+static inline int itd_slot_ok(struct fotg210_hcd *fotg210, u32 mod, u32 uframe,
+		u8 usecs, u32 period)
+{
+	uframe %= period;
+	do {
+		/* can't commit more than uframe_periodic_max usec */
+		if (periodic_usecs(fotg210, uframe >> 3, uframe & 0x7)
+				> (fotg210->uframe_periodic_max - usecs))
+			return 0;
+
+		/* we know urb->interval is 2^N uframes */
+		uframe += period;
+	} while (uframe < mod);
+	return 1;
+}
+
+/* This scheduler plans almost as far into the future as it has actual
+ * periodic schedule slots.  (Affected by TUNE_FLS, which defaults to
+ * "as small as possible" to be cache-friendlier.)  That limits the size
+ * transfers you can stream reliably; avoid more than 64 msec per urb.
+ * Also avoid queue depths of less than fotg210's worst irq latency (affected
+ * by the per-urb URB_NO_INTERRUPT hint, the log2_irq_thresh module parameter,
+ * and other factors); or more than about 230 msec total (for portability,
+ * given FOTG210_TUNE_FLS and the slop).  Or, write a smarter scheduler!
+ */
+
+#define SCHEDULE_SLOP 80 /* microframes */
+
+static int iso_stream_schedule(struct fotg210_hcd *fotg210, struct urb *urb,
+		struct fotg210_iso_stream *stream)
+{
+	u32 now, next, start, period, span;
+	int status;
+	unsigned mod = fotg210->periodic_size << 3;
+	struct fotg210_iso_sched *sched = urb->hcpriv;
+
+	period = urb->interval;
+	span = sched->span;
+
+	if (span > mod - SCHEDULE_SLOP) {
+		fotg210_dbg(fotg210, "iso request %p too long\n", urb);
+		status = -EFBIG;
+		goto fail;
+	}
+
+	now = fotg210_read_frame_index(fotg210) & (mod - 1);
+
+	/* Typical case: reuse current schedule, stream is still active.
+	 * Hopefully there are no gaps from the host falling behind
+	 * (irq delays etc), but if there are we'll take the next
+	 * slot in the schedule, implicitly assuming URB_ISO_ASAP.
+	 */
+	if (likely(!list_empty(&stream->td_list))) {
+		u32 excess;
+
+		/* For high speed devices, allow scheduling within the
+		 * isochronous scheduling threshold.  For full speed devices
+		 * and Intel PCI-based controllers, don't (work around for
+		 * Intel ICH9 bug).
+		 */
+		if (!stream->highspeed && fotg210->fs_i_thresh)
+			next = now + fotg210->i_thresh;
+		else
+			next = now;
+
+		/* Fell behind (by up to twice the slop amount)?
+		 * We decide based on the time of the last currently-scheduled
+		 * slot, not the time of the next available slot.
+		 */
+		excess = (stream->next_uframe - period - next) & (mod - 1);
+		if (excess >= mod - 2 * SCHEDULE_SLOP)
+			start = next + excess - mod + period *
+					DIV_ROUND_UP(mod - excess, period);
+		else
+			start = next + excess + period;
+		if (start - now >= mod) {
+			fotg210_dbg(fotg210, "request %p would overflow (%d+%d >= %d)\n",
+					urb, start - now - period, period,
+					mod);
+			status = -EFBIG;
+			goto fail;
+		}
+	}
+
+	/* need to schedule; when's the next (u)frame we could start?
+	 * this is bigger than fotg210->i_thresh allows; scheduling itself
+	 * isn't free, the slop should handle reasonably slow cpus.  it
+	 * can also help high bandwidth if the dma and irq loads don't
+	 * jump until after the queue is primed.
+	 */
+	else {
+		int done = 0;
+
+		start = SCHEDULE_SLOP + (now & ~0x07);
+
+		/* NOTE:  assumes URB_ISO_ASAP, to limit complexity/bugs */
+
+		/* find a uframe slot with enough bandwidth.
+		 * Early uframes are more precious because full-speed
+		 * iso IN transfers can't use late uframes,
+		 * and therefore they should be allocated last.
+		 */
+		next = start;
+		start += period;
+		do {
+			start--;
+			/* check schedule: enough space? */
+			if (itd_slot_ok(fotg210, mod, start,
+					stream->usecs, period))
+				done = 1;
+		} while (start > next && !done);
+
+		/* no room in the schedule */
+		if (!done) {
+			fotg210_dbg(fotg210, "iso resched full %p (now %d max %d)\n",
+					urb, now, now + mod);
+			status = -ENOSPC;
+			goto fail;
+		}
+	}
+
+	/* Tried to schedule too far into the future? */
+	if (unlikely(start - now + span - period >=
+			mod - 2 * SCHEDULE_SLOP)) {
+		fotg210_dbg(fotg210, "request %p would overflow (%d+%d >= %d)\n",
+				urb, start - now, span - period,
+				mod - 2 * SCHEDULE_SLOP);
+		status = -EFBIG;
+		goto fail;
+	}
+
+	stream->next_uframe = start & (mod - 1);
+
+	/* report high speed start in uframes; full speed, in frames */
+	urb->start_frame = stream->next_uframe;
+	if (!stream->highspeed)
+		urb->start_frame >>= 3;
+
+	/* Make sure scan_isoc() sees these */
+	if (fotg210->isoc_count == 0)
+		fotg210->next_frame = now >> 3;
+	return 0;
+
+fail:
+	iso_sched_free(stream, sched);
+	urb->hcpriv = NULL;
+	return status;
+}
+
+static inline void itd_init(struct fotg210_hcd *fotg210,
+		struct fotg210_iso_stream *stream, struct fotg210_itd *itd)
+{
+	int i;
+
+	/* it's been recently zeroed */
+	itd->hw_next = FOTG210_LIST_END(fotg210);
+	itd->hw_bufp[0] = stream->buf0;
+	itd->hw_bufp[1] = stream->buf1;
+	itd->hw_bufp[2] = stream->buf2;
+
+	for (i = 0; i < 8; i++)
+		itd->index[i] = -1;
+
+	/* All other fields are filled when scheduling */
+}
+
+static inline void itd_patch(struct fotg210_hcd *fotg210,
+		struct fotg210_itd *itd, struct fotg210_iso_sched *iso_sched,
+		unsigned index, u16 uframe)
+{
+	struct fotg210_iso_packet *uf = &iso_sched->packet[index];
+	unsigned pg = itd->pg;
+
+	uframe &= 0x07;
+	itd->index[uframe] = index;
+
+	itd->hw_transaction[uframe] = uf->transaction;
+	itd->hw_transaction[uframe] |= cpu_to_hc32(fotg210, pg << 12);
+	itd->hw_bufp[pg] |= cpu_to_hc32(fotg210, uf->bufp & ~(u32)0);
+	itd->hw_bufp_hi[pg] |= cpu_to_hc32(fotg210, (u32)(uf->bufp >> 32));
+
+	/* iso_frame_desc[].offset must be strictly increasing */
+	if (unlikely(uf->cross)) {
+		u64 bufp = uf->bufp + 4096;
+
+		itd->pg = ++pg;
+		itd->hw_bufp[pg] |= cpu_to_hc32(fotg210, bufp & ~(u32)0);
+		itd->hw_bufp_hi[pg] |= cpu_to_hc32(fotg210, (u32)(bufp >> 32));
+	}
+}
+
+static inline void itd_link(struct fotg210_hcd *fotg210, unsigned frame,
+		struct fotg210_itd *itd)
+{
+	union fotg210_shadow *prev = &fotg210->pshadow[frame];
+	__hc32 *hw_p = &fotg210->periodic[frame];
+	union fotg210_shadow here = *prev;
+	__hc32 type = 0;
+
+	/* skip any iso nodes which might belong to previous microframes */
+	while (here.ptr) {
+		type = Q_NEXT_TYPE(fotg210, *hw_p);
+		if (type == cpu_to_hc32(fotg210, Q_TYPE_QH))
+			break;
+		prev = periodic_next_shadow(fotg210, prev, type);
+		hw_p = shadow_next_periodic(fotg210, &here, type);
+		here = *prev;
+	}
+
+	itd->itd_next = here;
+	itd->hw_next = *hw_p;
+	prev->itd = itd;
+	itd->frame = frame;
+	wmb();
+	*hw_p = cpu_to_hc32(fotg210, itd->itd_dma | Q_TYPE_ITD);
+}
+
+/* fit urb's itds into the selected schedule slot; activate as needed */
+static void itd_link_urb(struct fotg210_hcd *fotg210, struct urb *urb,
+		unsigned mod, struct fotg210_iso_stream *stream)
+{
+	int packet;
+	unsigned next_uframe, uframe, frame;
+	struct fotg210_iso_sched *iso_sched = urb->hcpriv;
+	struct fotg210_itd *itd;
+
+	next_uframe = stream->next_uframe & (mod - 1);
+
+	if (unlikely(list_empty(&stream->td_list))) {
+		fotg210_to_hcd(fotg210)->self.bandwidth_allocated
+				+= stream->bandwidth;
+		fotg210_dbg(fotg210,
+			"schedule devp %s ep%d%s-iso period %d start %d.%d\n",
+			urb->dev->devpath, stream->bEndpointAddress & 0x0f,
+			(stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out",
+			urb->interval,
+			next_uframe >> 3, next_uframe & 0x7);
+	}
+
+	/* fill iTDs uframe by uframe */
+	for (packet = 0, itd = NULL; packet < urb->number_of_packets;) {
+		if (itd == NULL) {
+			/* ASSERT:  we have all necessary itds */
+
+			/* ASSERT:  no itds for this endpoint in this uframe */
+
+			itd = list_entry(iso_sched->td_list.next,
+					struct fotg210_itd, itd_list);
+			list_move_tail(&itd->itd_list, &stream->td_list);
+			itd->stream = stream;
+			itd->urb = urb;
+			itd_init(fotg210, stream, itd);
+		}
+
+		uframe = next_uframe & 0x07;
+		frame = next_uframe >> 3;
+
+		itd_patch(fotg210, itd, iso_sched, packet, uframe);
+
+		next_uframe += stream->interval;
+		next_uframe &= mod - 1;
+		packet++;
+
+		/* link completed itds into the schedule */
+		if (((next_uframe >> 3) != frame)
+				|| packet == urb->number_of_packets) {
+			itd_link(fotg210, frame & (fotg210->periodic_size - 1),
+					itd);
+			itd = NULL;
+		}
+	}
+	stream->next_uframe = next_uframe;
+
+	/* don't need that schedule data any more */
+	iso_sched_free(stream, iso_sched);
+	urb->hcpriv = NULL;
+
+	++fotg210->isoc_count;
+	enable_periodic(fotg210);
+}
+
+#define ISO_ERRS (FOTG210_ISOC_BUF_ERR | FOTG210_ISOC_BABBLE |\
+		FOTG210_ISOC_XACTERR)
+
+/* Process and recycle a completed ITD.  Return true iff its urb completed,
+ * and hence its completion callback probably added things to the hardware
+ * schedule.
+ *
+ * Note that we carefully avoid recycling this descriptor until after any
+ * completion callback runs, so that it won't be reused quickly.  That is,
+ * assuming (a) no more than two urbs per frame on this endpoint, and also
+ * (b) only this endpoint's completions submit URBs.  It seems some silicon
+ * corrupts things if you reuse completed descriptors very quickly...
+ */
+static bool itd_complete(struct fotg210_hcd *fotg210, struct fotg210_itd *itd)
+{
+	struct urb *urb = itd->urb;
+	struct usb_iso_packet_descriptor *desc;
+	u32 t;
+	unsigned uframe;
+	int urb_index = -1;
+	struct fotg210_iso_stream *stream = itd->stream;
+	struct usb_device *dev;
+	bool retval = false;
+
+	/* for each uframe with a packet */
+	for (uframe = 0; uframe < 8; uframe++) {
+		if (likely(itd->index[uframe] == -1))
+			continue;
+		urb_index = itd->index[uframe];
+		desc = &urb->iso_frame_desc[urb_index];
+
+		t = hc32_to_cpup(fotg210, &itd->hw_transaction[uframe]);
+		itd->hw_transaction[uframe] = 0;
+
+		/* report transfer status */
+		if (unlikely(t & ISO_ERRS)) {
+			urb->error_count++;
+			if (t & FOTG210_ISOC_BUF_ERR)
+				desc->status = usb_pipein(urb->pipe)
+					? -ENOSR  /* hc couldn't read */
+					: -ECOMM; /* hc couldn't write */
+			else if (t & FOTG210_ISOC_BABBLE)
+				desc->status = -EOVERFLOW;
+			else /* (t & FOTG210_ISOC_XACTERR) */
+				desc->status = -EPROTO;
+
+			/* HC need not update length with this error */
+			if (!(t & FOTG210_ISOC_BABBLE)) {
+				desc->actual_length = FOTG210_ITD_LENGTH(t);
+				urb->actual_length += desc->actual_length;
+			}
+		} else if (likely((t & FOTG210_ISOC_ACTIVE) == 0)) {
+			desc->status = 0;
+			desc->actual_length = FOTG210_ITD_LENGTH(t);
+			urb->actual_length += desc->actual_length;
+		} else {
+			/* URB was too late */
+			desc->status = -EXDEV;
+		}
+	}
+
+	/* handle completion now? */
+	if (likely((urb_index + 1) != urb->number_of_packets))
+		goto done;
+
+	/* ASSERT: it's really the last itd for this urb
+	 * list_for_each_entry (itd, &stream->td_list, itd_list)
+	 *	BUG_ON (itd->urb == urb);
+	 */
+
+	/* give urb back to the driver; completion often (re)submits */
+	dev = urb->dev;
+	fotg210_urb_done(fotg210, urb, 0);
+	retval = true;
+	urb = NULL;
+
+	--fotg210->isoc_count;
+	disable_periodic(fotg210);
+
+	if (unlikely(list_is_singular(&stream->td_list))) {
+		fotg210_to_hcd(fotg210)->self.bandwidth_allocated
+				-= stream->bandwidth;
+		fotg210_dbg(fotg210,
+			"deschedule devp %s ep%d%s-iso\n",
+			dev->devpath, stream->bEndpointAddress & 0x0f,
+			(stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
+	}
+
+done:
+	itd->urb = NULL;
+
+	/* Add to the end of the free list for later reuse */
+	list_move_tail(&itd->itd_list, &stream->free_list);
+
+	/* Recycle the iTDs when the pipeline is empty (ep no longer in use) */
+	if (list_empty(&stream->td_list)) {
+		list_splice_tail_init(&stream->free_list,
+				&fotg210->cached_itd_list);
+		start_free_itds(fotg210);
+	}
+
+	return retval;
+}
+
+static int itd_submit(struct fotg210_hcd *fotg210, struct urb *urb,
+		gfp_t mem_flags)
+{
+	int status = -EINVAL;
+	unsigned long flags;
+	struct fotg210_iso_stream *stream;
+
+	/* Get iso_stream head */
+	stream = iso_stream_find(fotg210, urb);
+	if (unlikely(stream == NULL)) {
+		fotg210_dbg(fotg210, "can't get iso stream\n");
+		return -ENOMEM;
+	}
+	if (unlikely(urb->interval != stream->interval &&
+			fotg210_port_speed(fotg210, 0) ==
+			USB_PORT_STAT_HIGH_SPEED)) {
+		fotg210_dbg(fotg210, "can't change iso interval %d --> %d\n",
+				stream->interval, urb->interval);
+		goto done;
+	}
+
+#ifdef FOTG210_URB_TRACE
+	fotg210_dbg(fotg210,
+			"%s %s urb %p ep%d%s len %d, %d pkts %d uframes[%p]\n",
+			__func__, urb->dev->devpath, urb,
+			usb_pipeendpoint(urb->pipe),
+			usb_pipein(urb->pipe) ? "in" : "out",
+			urb->transfer_buffer_length,
+			urb->number_of_packets, urb->interval,
+			stream);
+#endif
+
+	/* allocate ITDs w/o locking anything */
+	status = itd_urb_transaction(stream, fotg210, urb, mem_flags);
+	if (unlikely(status < 0)) {
+		fotg210_dbg(fotg210, "can't init itds\n");
+		goto done;
+	}
+
+	/* schedule ... need to lock */
+	spin_lock_irqsave(&fotg210->lock, flags);
+	if (unlikely(!HCD_HW_ACCESSIBLE(fotg210_to_hcd(fotg210)))) {
+		status = -ESHUTDOWN;
+		goto done_not_linked;
+	}
+	status = usb_hcd_link_urb_to_ep(fotg210_to_hcd(fotg210), urb);
+	if (unlikely(status))
+		goto done_not_linked;
+	status = iso_stream_schedule(fotg210, urb, stream);
+	if (likely(status == 0))
+		itd_link_urb(fotg210, urb, fotg210->periodic_size << 3, stream);
+	else
+		usb_hcd_unlink_urb_from_ep(fotg210_to_hcd(fotg210), urb);
+done_not_linked:
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+done:
+	return status;
+}
+
+static inline int scan_frame_queue(struct fotg210_hcd *fotg210, unsigned frame,
+		unsigned now_frame, bool live)
+{
+	unsigned uf;
+	bool modified;
+	union fotg210_shadow q, *q_p;
+	__hc32 type, *hw_p;
+
+	/* scan each element in frame's queue for completions */
+	q_p = &fotg210->pshadow[frame];
+	hw_p = &fotg210->periodic[frame];
+	q.ptr = q_p->ptr;
+	type = Q_NEXT_TYPE(fotg210, *hw_p);
+	modified = false;
+
+	while (q.ptr) {
+		switch (hc32_to_cpu(fotg210, type)) {
+		case Q_TYPE_ITD:
+			/* If this ITD is still active, leave it for
+			 * later processing ... check the next entry.
+			 * No need to check for activity unless the
+			 * frame is current.
+			 */
+			if (frame == now_frame && live) {
+				rmb();
+				for (uf = 0; uf < 8; uf++) {
+					if (q.itd->hw_transaction[uf] &
+							ITD_ACTIVE(fotg210))
+						break;
+				}
+				if (uf < 8) {
+					q_p = &q.itd->itd_next;
+					hw_p = &q.itd->hw_next;
+					type = Q_NEXT_TYPE(fotg210,
+							q.itd->hw_next);
+					q = *q_p;
+					break;
+				}
+			}
+
+			/* Take finished ITDs out of the schedule
+			 * and process them:  recycle, maybe report
+			 * URB completion.  HC won't cache the
+			 * pointer for much longer, if at all.
+			 */
+			*q_p = q.itd->itd_next;
+			*hw_p = q.itd->hw_next;
+			type = Q_NEXT_TYPE(fotg210, q.itd->hw_next);
+			wmb();
+			modified = itd_complete(fotg210, q.itd);
+			q = *q_p;
+			break;
+		default:
+			fotg210_dbg(fotg210, "corrupt type %d frame %d shadow %p\n",
+					type, frame, q.ptr);
+			fallthrough;
+		case Q_TYPE_QH:
+		case Q_TYPE_FSTN:
+			/* End of the iTDs and siTDs */
+			q.ptr = NULL;
+			break;
+		}
+
+		/* assume completion callbacks modify the queue */
+		if (unlikely(modified && fotg210->isoc_count > 0))
+			return -EINVAL;
+	}
+	return 0;
+}
+
+static void scan_isoc(struct fotg210_hcd *fotg210)
+{
+	unsigned uf, now_frame, frame, ret;
+	unsigned fmask = fotg210->periodic_size - 1;
+	bool live;
+
+	/*
+	 * When running, scan from last scan point up to "now"
+	 * else clean up by scanning everything that's left.
+	 * Touches as few pages as possible:  cache-friendly.
+	 */
+	if (fotg210->rh_state >= FOTG210_RH_RUNNING) {
+		uf = fotg210_read_frame_index(fotg210);
+		now_frame = (uf >> 3) & fmask;
+		live = true;
+	} else  {
+		now_frame = (fotg210->next_frame - 1) & fmask;
+		live = false;
+	}
+	fotg210->now_frame = now_frame;
+
+	frame = fotg210->next_frame;
+	for (;;) {
+		ret = 1;
+		while (ret != 0)
+			ret = scan_frame_queue(fotg210, frame,
+					now_frame, live);
+
+		/* Stop when we have reached the current frame */
+		if (frame == now_frame)
+			break;
+		frame = (frame + 1) & fmask;
+	}
+	fotg210->next_frame = now_frame;
+}
+
+/* Display / Set uframe_periodic_max
+ */
+static ssize_t uframe_periodic_max_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct fotg210_hcd *fotg210;
+
+	fotg210 = hcd_to_fotg210(bus_to_hcd(dev_get_drvdata(dev)));
+	return sysfs_emit(buf, "%d\n", fotg210->uframe_periodic_max);
+}
+
+static ssize_t uframe_periodic_max_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct fotg210_hcd *fotg210;
+	unsigned uframe_periodic_max;
+	unsigned frame, uframe;
+	unsigned short allocated_max;
+	unsigned long flags;
+	ssize_t ret;
+
+	fotg210 = hcd_to_fotg210(bus_to_hcd(dev_get_drvdata(dev)));
+
+	ret = kstrtouint(buf, 0, &uframe_periodic_max);
+	if (ret)
+		return ret;
+
+	if (uframe_periodic_max < 100 || uframe_periodic_max >= 125) {
+		fotg210_info(fotg210, "rejecting invalid request for uframe_periodic_max=%u\n",
+				uframe_periodic_max);
+		return -EINVAL;
+	}
+
+	ret = -EINVAL;
+
+	/*
+	 * lock, so that our checking does not race with possible periodic
+	 * bandwidth allocation through submitting new urbs.
+	 */
+	spin_lock_irqsave(&fotg210->lock, flags);
+
+	/*
+	 * for request to decrease max periodic bandwidth, we have to check
+	 * every microframe in the schedule to see whether the decrease is
+	 * possible.
+	 */
+	if (uframe_periodic_max < fotg210->uframe_periodic_max) {
+		allocated_max = 0;
+
+		for (frame = 0; frame < fotg210->periodic_size; ++frame)
+			for (uframe = 0; uframe < 7; ++uframe)
+				allocated_max = max(allocated_max,
+						periodic_usecs(fotg210, frame,
+						uframe));
+
+		if (allocated_max > uframe_periodic_max) {
+			fotg210_info(fotg210,
+					"cannot decrease uframe_periodic_max because periodic bandwidth is already allocated (%u > %u)\n",
+					allocated_max, uframe_periodic_max);
+			goto out_unlock;
+		}
+	}
+
+	/* increasing is always ok */
+
+	fotg210_info(fotg210,
+			"setting max periodic bandwidth to %u%% (== %u usec/uframe)\n",
+			100 * uframe_periodic_max/125, uframe_periodic_max);
+
+	if (uframe_periodic_max != 100)
+		fotg210_warn(fotg210, "max periodic bandwidth set is non-standard\n");
+
+	fotg210->uframe_periodic_max = uframe_periodic_max;
+	ret = count;
+
+out_unlock:
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	return ret;
+}
+
+static DEVICE_ATTR_RW(uframe_periodic_max);
+
+static inline int create_sysfs_files(struct fotg210_hcd *fotg210)
+{
+	struct device *controller = fotg210_to_hcd(fotg210)->self.controller;
+
+	return device_create_file(controller, &dev_attr_uframe_periodic_max);
+}
+
+static inline void remove_sysfs_files(struct fotg210_hcd *fotg210)
+{
+	struct device *controller = fotg210_to_hcd(fotg210)->self.controller;
+
+	device_remove_file(controller, &dev_attr_uframe_periodic_max);
+}
+/* On some systems, leaving remote wakeup enabled prevents system shutdown.
+ * The firmware seems to think that powering off is a wakeup event!
+ * This routine turns off remote wakeup and everything else, on all ports.
+ */
+static void fotg210_turn_off_all_ports(struct fotg210_hcd *fotg210)
+{
+	u32 __iomem *status_reg = &fotg210->regs->port_status;
+
+	fotg210_writel(fotg210, PORT_RWC_BITS, status_reg);
+}
+
+/* Halt HC, turn off all ports, and let the BIOS use the companion controllers.
+ * Must be called with interrupts enabled and the lock not held.
+ */
+static void fotg210_silence_controller(struct fotg210_hcd *fotg210)
+{
+	fotg210_halt(fotg210);
+
+	spin_lock_irq(&fotg210->lock);
+	fotg210->rh_state = FOTG210_RH_HALTED;
+	fotg210_turn_off_all_ports(fotg210);
+	spin_unlock_irq(&fotg210->lock);
+}
+
+/* fotg210_shutdown kick in for silicon on any bus (not just pci, etc).
+ * This forcibly disables dma and IRQs, helping kexec and other cases
+ * where the next system software may expect clean state.
+ */
+static void fotg210_shutdown(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+
+	spin_lock_irq(&fotg210->lock);
+	fotg210->shutdown = true;
+	fotg210->rh_state = FOTG210_RH_STOPPING;
+	fotg210->enabled_hrtimer_events = 0;
+	spin_unlock_irq(&fotg210->lock);
+
+	fotg210_silence_controller(fotg210);
+
+	hrtimer_cancel(&fotg210->hrtimer);
+}
+
+/* fotg210_work is called from some interrupts, timers, and so on.
+ * it calls driver completion functions, after dropping fotg210->lock.
+ */
+static void fotg210_work(struct fotg210_hcd *fotg210)
+{
+	/* another CPU may drop fotg210->lock during a schedule scan while
+	 * it reports urb completions.  this flag guards against bogus
+	 * attempts at re-entrant schedule scanning.
+	 */
+	if (fotg210->scanning) {
+		fotg210->need_rescan = true;
+		return;
+	}
+	fotg210->scanning = true;
+
+rescan:
+	fotg210->need_rescan = false;
+	if (fotg210->async_count)
+		scan_async(fotg210);
+	if (fotg210->intr_count > 0)
+		scan_intr(fotg210);
+	if (fotg210->isoc_count > 0)
+		scan_isoc(fotg210);
+	if (fotg210->need_rescan)
+		goto rescan;
+	fotg210->scanning = false;
+
+	/* the IO watchdog guards against hardware or driver bugs that
+	 * misplace IRQs, and should let us run completely without IRQs.
+	 * such lossage has been observed on both VT6202 and VT8235.
+	 */
+	turn_on_io_watchdog(fotg210);
+}
+
+/* Called when the fotg210_hcd module is removed.
+ */
+static void fotg210_stop(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+
+	fotg210_dbg(fotg210, "stop\n");
+
+	/* no more interrupts ... */
+
+	spin_lock_irq(&fotg210->lock);
+	fotg210->enabled_hrtimer_events = 0;
+	spin_unlock_irq(&fotg210->lock);
+
+	fotg210_quiesce(fotg210);
+	fotg210_silence_controller(fotg210);
+	fotg210_reset(fotg210);
+
+	hrtimer_cancel(&fotg210->hrtimer);
+	remove_sysfs_files(fotg210);
+	remove_debug_files(fotg210);
+
+	/* root hub is shut down separately (first, when possible) */
+	spin_lock_irq(&fotg210->lock);
+	end_free_itds(fotg210);
+	spin_unlock_irq(&fotg210->lock);
+	fotg210_mem_cleanup(fotg210);
+
+#ifdef FOTG210_STATS
+	fotg210_dbg(fotg210, "irq normal %ld err %ld iaa %ld (lost %ld)\n",
+			fotg210->stats.normal, fotg210->stats.error,
+			fotg210->stats.iaa, fotg210->stats.lost_iaa);
+	fotg210_dbg(fotg210, "complete %ld unlink %ld\n",
+			fotg210->stats.complete, fotg210->stats.unlink);
+#endif
+
+	dbg_status(fotg210, "fotg210_stop completed",
+			fotg210_readl(fotg210, &fotg210->regs->status));
+}
+
+/* one-time init, only for memory state */
+static int hcd_fotg210_init(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+	u32 temp;
+	int retval;
+	u32 hcc_params;
+	struct fotg210_qh_hw *hw;
+
+	spin_lock_init(&fotg210->lock);
+
+	/*
+	 * keep io watchdog by default, those good HCDs could turn off it later
+	 */
+	fotg210->need_io_watchdog = 1;
+
+	hrtimer_init(&fotg210->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	fotg210->hrtimer.function = fotg210_hrtimer_func;
+	fotg210->next_hrtimer_event = FOTG210_HRTIMER_NO_EVENT;
+
+	hcc_params = fotg210_readl(fotg210, &fotg210->caps->hcc_params);
+
+	/*
+	 * by default set standard 80% (== 100 usec/uframe) max periodic
+	 * bandwidth as required by USB 2.0
+	 */
+	fotg210->uframe_periodic_max = 100;
+
+	/*
+	 * hw default: 1K periodic list heads, one per frame.
+	 * periodic_size can shrink by USBCMD update if hcc_params allows.
+	 */
+	fotg210->periodic_size = DEFAULT_I_TDPS;
+	INIT_LIST_HEAD(&fotg210->intr_qh_list);
+	INIT_LIST_HEAD(&fotg210->cached_itd_list);
+
+	if (HCC_PGM_FRAMELISTLEN(hcc_params)) {
+		/* periodic schedule size can be smaller than default */
+		switch (FOTG210_TUNE_FLS) {
+		case 0:
+			fotg210->periodic_size = 1024;
+			break;
+		case 1:
+			fotg210->periodic_size = 512;
+			break;
+		case 2:
+			fotg210->periodic_size = 256;
+			break;
+		default:
+			BUG();
+		}
+	}
+	retval = fotg210_mem_init(fotg210, GFP_KERNEL);
+	if (retval < 0)
+		return retval;
+
+	/* controllers may cache some of the periodic schedule ... */
+	fotg210->i_thresh = 2;
+
+	/*
+	 * dedicate a qh for the async ring head, since we couldn't unlink
+	 * a 'real' qh without stopping the async schedule [4.8].  use it
+	 * as the 'reclamation list head' too.
+	 * its dummy is used in hw_alt_next of many tds, to prevent the qh
+	 * from automatically advancing to the next td after short reads.
+	 */
+	fotg210->async->qh_next.qh = NULL;
+	hw = fotg210->async->hw;
+	hw->hw_next = QH_NEXT(fotg210, fotg210->async->qh_dma);
+	hw->hw_info1 = cpu_to_hc32(fotg210, QH_HEAD);
+	hw->hw_token = cpu_to_hc32(fotg210, QTD_STS_HALT);
+	hw->hw_qtd_next = FOTG210_LIST_END(fotg210);
+	fotg210->async->qh_state = QH_STATE_LINKED;
+	hw->hw_alt_next = QTD_NEXT(fotg210, fotg210->async->dummy->qtd_dma);
+
+	/* clear interrupt enables, set irq latency */
+	if (log2_irq_thresh < 0 || log2_irq_thresh > 6)
+		log2_irq_thresh = 0;
+	temp = 1 << (16 + log2_irq_thresh);
+	if (HCC_CANPARK(hcc_params)) {
+		/* HW default park == 3, on hardware that supports it (like
+		 * NVidia and ALI silicon), maximizes throughput on the async
+		 * schedule by avoiding QH fetches between transfers.
+		 *
+		 * With fast usb storage devices and NForce2, "park" seems to
+		 * make problems:  throughput reduction (!), data errors...
+		 */
+		if (park) {
+			park = min_t(unsigned, park, 3);
+			temp |= CMD_PARK;
+			temp |= park << 8;
+		}
+		fotg210_dbg(fotg210, "park %d\n", park);
+	}
+	if (HCC_PGM_FRAMELISTLEN(hcc_params)) {
+		/* periodic schedule size can be smaller than default */
+		temp &= ~(3 << 2);
+		temp |= (FOTG210_TUNE_FLS << 2);
+	}
+	fotg210->command = temp;
+
+	/* Accept arbitrarily long scatter-gather lists */
+	if (!hcd->localmem_pool)
+		hcd->self.sg_tablesize = ~0;
+	return 0;
+}
+
+/* start HC running; it's halted, hcd_fotg210_init() has been run (once) */
+static int fotg210_run(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+	u32 temp;
+
+	hcd->uses_new_polling = 1;
+
+	/* EHCI spec section 4.1 */
+
+	fotg210_writel(fotg210, fotg210->periodic_dma,
+			&fotg210->regs->frame_list);
+	fotg210_writel(fotg210, (u32)fotg210->async->qh_dma,
+			&fotg210->regs->async_next);
+
+	/*
+	 * hcc_params controls whether fotg210->regs->segment must (!!!)
+	 * be used; it constrains QH/ITD/SITD and QTD locations.
+	 * dma_pool consistent memory always uses segment zero.
+	 * streaming mappings for I/O buffers, like dma_map_single(),
+	 * can return segments above 4GB, if the device allows.
+	 *
+	 * NOTE:  the dma mask is visible through dev->dma_mask, so
+	 * drivers can pass this info along ... like NETIF_F_HIGHDMA,
+	 * Scsi_Host.highmem_io, and so forth.  It's readonly to all
+	 * host side drivers though.
+	 */
+	fotg210_readl(fotg210, &fotg210->caps->hcc_params);
+
+	/*
+	 * Philips, Intel, and maybe others need CMD_RUN before the
+	 * root hub will detect new devices (why?); NEC doesn't
+	 */
+	fotg210->command &= ~(CMD_IAAD|CMD_PSE|CMD_ASE|CMD_RESET);
+	fotg210->command |= CMD_RUN;
+	fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
+	dbg_cmd(fotg210, "init", fotg210->command);
+
+	/*
+	 * Start, enabling full USB 2.0 functionality ... usb 1.1 devices
+	 * are explicitly handed to companion controller(s), so no TT is
+	 * involved with the root hub.  (Except where one is integrated,
+	 * and there's no companion controller unless maybe for USB OTG.)
+	 *
+	 * Turning on the CF flag will transfer ownership of all ports
+	 * from the companions to the EHCI controller.  If any of the
+	 * companions are in the middle of a port reset at the time, it
+	 * could cause trouble.  Write-locking ehci_cf_port_reset_rwsem
+	 * guarantees that no resets are in progress.  After we set CF,
+	 * a short delay lets the hardware catch up; new resets shouldn't
+	 * be started before the port switching actions could complete.
+	 */
+	down_write(&ehci_cf_port_reset_rwsem);
+	fotg210->rh_state = FOTG210_RH_RUNNING;
+	/* unblock posted writes */
+	fotg210_readl(fotg210, &fotg210->regs->command);
+	usleep_range(5000, 10000);
+	up_write(&ehci_cf_port_reset_rwsem);
+	fotg210->last_periodic_enable = ktime_get_real();
+
+	temp = HC_VERSION(fotg210,
+			fotg210_readl(fotg210, &fotg210->caps->hc_capbase));
+	fotg210_info(fotg210,
+			"USB %x.%x started, EHCI %x.%02x\n",
+			((fotg210->sbrn & 0xf0) >> 4), (fotg210->sbrn & 0x0f),
+			temp >> 8, temp & 0xff);
+
+	fotg210_writel(fotg210, INTR_MASK,
+			&fotg210->regs->intr_enable); /* Turn On Interrupts */
+
+	/* GRR this is run-once init(), being done every time the HC starts.
+	 * So long as they're part of class devices, we can't do it init()
+	 * since the class device isn't created that early.
+	 */
+	create_debug_files(fotg210);
+	create_sysfs_files(fotg210);
+
+	return 0;
+}
+
+static int fotg210_setup(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+	int retval;
+
+	fotg210->regs = (void __iomem *)fotg210->caps +
+			HC_LENGTH(fotg210,
+			fotg210_readl(fotg210, &fotg210->caps->hc_capbase));
+	dbg_hcs_params(fotg210, "reset");
+	dbg_hcc_params(fotg210, "reset");
+
+	/* cache this readonly data; minimize chip reads */
+	fotg210->hcs_params = fotg210_readl(fotg210,
+			&fotg210->caps->hcs_params);
+
+	fotg210->sbrn = HCD_USB2;
+
+	/* data structure init */
+	retval = hcd_fotg210_init(hcd);
+	if (retval)
+		return retval;
+
+	retval = fotg210_halt(fotg210);
+	if (retval)
+		return retval;
+
+	fotg210_reset(fotg210);
+
+	return 0;
+}
+
+static irqreturn_t fotg210_irq(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+	u32 status, masked_status, pcd_status = 0, cmd;
+	int bh;
+
+	spin_lock(&fotg210->lock);
+
+	status = fotg210_readl(fotg210, &fotg210->regs->status);
+
+	/* e.g. cardbus physical eject */
+	if (status == ~(u32) 0) {
+		fotg210_dbg(fotg210, "device removed\n");
+		goto dead;
+	}
+
+	/*
+	 * We don't use STS_FLR, but some controllers don't like it to
+	 * remain on, so mask it out along with the other status bits.
+	 */
+	masked_status = status & (INTR_MASK | STS_FLR);
+
+	/* Shared IRQ? */
+	if (!masked_status ||
+			unlikely(fotg210->rh_state == FOTG210_RH_HALTED)) {
+		spin_unlock(&fotg210->lock);
+		return IRQ_NONE;
+	}
+
+	/* clear (just) interrupts */
+	fotg210_writel(fotg210, masked_status, &fotg210->regs->status);
+	cmd = fotg210_readl(fotg210, &fotg210->regs->command);
+	bh = 0;
+
+	/* unrequested/ignored: Frame List Rollover */
+	dbg_status(fotg210, "irq", status);
+
+	/* INT, ERR, and IAA interrupt rates can be throttled */
+
+	/* normal [4.15.1.2] or error [4.15.1.1] completion */
+	if (likely((status & (STS_INT|STS_ERR)) != 0)) {
+		if (likely((status & STS_ERR) == 0))
+			INCR(fotg210->stats.normal);
+		else
+			INCR(fotg210->stats.error);
+		bh = 1;
+	}
+
+	/* complete the unlinking of some qh [4.15.2.3] */
+	if (status & STS_IAA) {
+
+		/* Turn off the IAA watchdog */
+		fotg210->enabled_hrtimer_events &=
+			~BIT(FOTG210_HRTIMER_IAA_WATCHDOG);
+
+		/*
+		 * Mild optimization: Allow another IAAD to reset the
+		 * hrtimer, if one occurs before the next expiration.
+		 * In theory we could always cancel the hrtimer, but
+		 * tests show that about half the time it will be reset
+		 * for some other event anyway.
+		 */
+		if (fotg210->next_hrtimer_event == FOTG210_HRTIMER_IAA_WATCHDOG)
+			++fotg210->next_hrtimer_event;
+
+		/* guard against (alleged) silicon errata */
+		if (cmd & CMD_IAAD)
+			fotg210_dbg(fotg210, "IAA with IAAD still set?\n");
+		if (fotg210->async_iaa) {
+			INCR(fotg210->stats.iaa);
+			end_unlink_async(fotg210);
+		} else
+			fotg210_dbg(fotg210, "IAA with nothing unlinked?\n");
+	}
+
+	/* remote wakeup [4.3.1] */
+	if (status & STS_PCD) {
+		int pstatus;
+		u32 __iomem *status_reg = &fotg210->regs->port_status;
+
+		/* kick root hub later */
+		pcd_status = status;
+
+		/* resume root hub? */
+		if (fotg210->rh_state == FOTG210_RH_SUSPENDED)
+			usb_hcd_resume_root_hub(hcd);
+
+		pstatus = fotg210_readl(fotg210, status_reg);
+
+		if (test_bit(0, &fotg210->suspended_ports) &&
+				((pstatus & PORT_RESUME) ||
+				!(pstatus & PORT_SUSPEND)) &&
+				(pstatus & PORT_PE) &&
+				fotg210->reset_done[0] == 0) {
+
+			/* start 20 msec resume signaling from this port,
+			 * and make hub_wq collect PORT_STAT_C_SUSPEND to
+			 * stop that signaling.  Use 5 ms extra for safety,
+			 * like usb_port_resume() does.
+			 */
+			fotg210->reset_done[0] = jiffies + msecs_to_jiffies(25);
+			set_bit(0, &fotg210->resuming_ports);
+			fotg210_dbg(fotg210, "port 1 remote wakeup\n");
+			mod_timer(&hcd->rh_timer, fotg210->reset_done[0]);
+		}
+	}
+
+	/* PCI errors [4.15.2.4] */
+	if (unlikely((status & STS_FATAL) != 0)) {
+		fotg210_err(fotg210, "fatal error\n");
+		dbg_cmd(fotg210, "fatal", cmd);
+		dbg_status(fotg210, "fatal", status);
+dead:
+		usb_hc_died(hcd);
+
+		/* Don't let the controller do anything more */
+		fotg210->shutdown = true;
+		fotg210->rh_state = FOTG210_RH_STOPPING;
+		fotg210->command &= ~(CMD_RUN | CMD_ASE | CMD_PSE);
+		fotg210_writel(fotg210, fotg210->command,
+				&fotg210->regs->command);
+		fotg210_writel(fotg210, 0, &fotg210->regs->intr_enable);
+		fotg210_handle_controller_death(fotg210);
+
+		/* Handle completions when the controller stops */
+		bh = 0;
+	}
+
+	if (bh)
+		fotg210_work(fotg210);
+	spin_unlock(&fotg210->lock);
+	if (pcd_status)
+		usb_hcd_poll_rh_status(hcd);
+	return IRQ_HANDLED;
+}
+
+/* non-error returns are a promise to giveback() the urb later
+ * we drop ownership so next owner (or urb unlink) can get it
+ *
+ * urb + dev is in hcd.self.controller.urb_list
+ * we're queueing TDs onto software and hardware lists
+ *
+ * hcd-specific init for hcpriv hasn't been done yet
+ *
+ * NOTE:  control, bulk, and interrupt share the same code to append TDs
+ * to a (possibly active) QH, and the same QH scanning code.
+ */
+static int fotg210_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
+		gfp_t mem_flags)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+	struct list_head qtd_list;
+
+	INIT_LIST_HEAD(&qtd_list);
+
+	switch (usb_pipetype(urb->pipe)) {
+	case PIPE_CONTROL:
+		/* qh_completions() code doesn't handle all the fault cases
+		 * in multi-TD control transfers.  Even 1KB is rare anyway.
+		 */
+		if (urb->transfer_buffer_length > (16 * 1024))
+			return -EMSGSIZE;
+		fallthrough;
+	/* case PIPE_BULK: */
+	default:
+		if (!qh_urb_transaction(fotg210, urb, &qtd_list, mem_flags))
+			return -ENOMEM;
+		return submit_async(fotg210, urb, &qtd_list, mem_flags);
+
+	case PIPE_INTERRUPT:
+		if (!qh_urb_transaction(fotg210, urb, &qtd_list, mem_flags))
+			return -ENOMEM;
+		return intr_submit(fotg210, urb, &qtd_list, mem_flags);
+
+	case PIPE_ISOCHRONOUS:
+		return itd_submit(fotg210, urb, mem_flags);
+	}
+}
+
+/* remove from hardware lists
+ * completions normally happen asynchronously
+ */
+
+static int fotg210_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+	struct fotg210_qh *qh;
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
+	if (rc)
+		goto done;
+
+	switch (usb_pipetype(urb->pipe)) {
+	/* case PIPE_CONTROL: */
+	/* case PIPE_BULK:*/
+	default:
+		qh = (struct fotg210_qh *) urb->hcpriv;
+		if (!qh)
+			break;
+		switch (qh->qh_state) {
+		case QH_STATE_LINKED:
+		case QH_STATE_COMPLETING:
+			start_unlink_async(fotg210, qh);
+			break;
+		case QH_STATE_UNLINK:
+		case QH_STATE_UNLINK_WAIT:
+			/* already started */
+			break;
+		case QH_STATE_IDLE:
+			/* QH might be waiting for a Clear-TT-Buffer */
+			qh_completions(fotg210, qh);
+			break;
+		}
+		break;
+
+	case PIPE_INTERRUPT:
+		qh = (struct fotg210_qh *) urb->hcpriv;
+		if (!qh)
+			break;
+		switch (qh->qh_state) {
+		case QH_STATE_LINKED:
+		case QH_STATE_COMPLETING:
+			start_unlink_intr(fotg210, qh);
+			break;
+		case QH_STATE_IDLE:
+			qh_completions(fotg210, qh);
+			break;
+		default:
+			fotg210_dbg(fotg210, "bogus qh %p state %d\n",
+					qh, qh->qh_state);
+			goto done;
+		}
+		break;
+
+	case PIPE_ISOCHRONOUS:
+		/* itd... */
+
+		/* wait till next completion, do it then. */
+		/* completion irqs can wait up to 1024 msec, */
+		break;
+	}
+done:
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	return rc;
+}
+
+/* bulk qh holds the data toggle */
+
+static void fotg210_endpoint_disable(struct usb_hcd *hcd,
+		struct usb_host_endpoint *ep)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+	unsigned long flags;
+	struct fotg210_qh *qh, *tmp;
+
+	/* ASSERT:  any requests/urbs are being unlinked */
+	/* ASSERT:  nobody can be submitting urbs for this any more */
+
+rescan:
+	spin_lock_irqsave(&fotg210->lock, flags);
+	qh = ep->hcpriv;
+	if (!qh)
+		goto done;
+
+	/* endpoints can be iso streams.  for now, we don't
+	 * accelerate iso completions ... so spin a while.
+	 */
+	if (qh->hw == NULL) {
+		struct fotg210_iso_stream *stream = ep->hcpriv;
+
+		if (!list_empty(&stream->td_list))
+			goto idle_timeout;
+
+		/* BUG_ON(!list_empty(&stream->free_list)); */
+		kfree(stream);
+		goto done;
+	}
+
+	if (fotg210->rh_state < FOTG210_RH_RUNNING)
+		qh->qh_state = QH_STATE_IDLE;
+	switch (qh->qh_state) {
+	case QH_STATE_LINKED:
+	case QH_STATE_COMPLETING:
+		for (tmp = fotg210->async->qh_next.qh;
+				tmp && tmp != qh;
+				tmp = tmp->qh_next.qh)
+			continue;
+		/* periodic qh self-unlinks on empty, and a COMPLETING qh
+		 * may already be unlinked.
+		 */
+		if (tmp)
+			start_unlink_async(fotg210, qh);
+		fallthrough;
+	case QH_STATE_UNLINK:		/* wait for hw to finish? */
+	case QH_STATE_UNLINK_WAIT:
+idle_timeout:
+		spin_unlock_irqrestore(&fotg210->lock, flags);
+		schedule_timeout_uninterruptible(1);
+		goto rescan;
+	case QH_STATE_IDLE:		/* fully unlinked */
+		if (qh->clearing_tt)
+			goto idle_timeout;
+		if (list_empty(&qh->qtd_list)) {
+			qh_destroy(fotg210, qh);
+			break;
+		}
+		fallthrough;
+	default:
+		/* caller was supposed to have unlinked any requests;
+		 * that's not our job.  just leak this memory.
+		 */
+		fotg210_err(fotg210, "qh %p (#%02x) state %d%s\n",
+				qh, ep->desc.bEndpointAddress, qh->qh_state,
+				list_empty(&qh->qtd_list) ? "" : "(has tds)");
+		break;
+	}
+done:
+	ep->hcpriv = NULL;
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+}
+
+static void fotg210_endpoint_reset(struct usb_hcd *hcd,
+		struct usb_host_endpoint *ep)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+	struct fotg210_qh *qh;
+	int eptype = usb_endpoint_type(&ep->desc);
+	int epnum = usb_endpoint_num(&ep->desc);
+	int is_out = usb_endpoint_dir_out(&ep->desc);
+	unsigned long flags;
+
+	if (eptype != USB_ENDPOINT_XFER_BULK && eptype != USB_ENDPOINT_XFER_INT)
+		return;
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+	qh = ep->hcpriv;
+
+	/* For Bulk and Interrupt endpoints we maintain the toggle state
+	 * in the hardware; the toggle bits in udev aren't used at all.
+	 * When an endpoint is reset by usb_clear_halt() we must reset
+	 * the toggle bit in the QH.
+	 */
+	if (qh) {
+		usb_settoggle(qh->dev, epnum, is_out, 0);
+		if (!list_empty(&qh->qtd_list)) {
+			WARN_ONCE(1, "clear_halt for a busy endpoint\n");
+		} else if (qh->qh_state == QH_STATE_LINKED ||
+				qh->qh_state == QH_STATE_COMPLETING) {
+
+			/* The toggle value in the QH can't be updated
+			 * while the QH is active.  Unlink it now;
+			 * re-linking will call qh_refresh().
+			 */
+			if (eptype == USB_ENDPOINT_XFER_BULK)
+				start_unlink_async(fotg210, qh);
+			else
+				start_unlink_intr(fotg210, qh);
+		}
+	}
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+}
+
+static int fotg210_get_frame(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+
+	return (fotg210_read_frame_index(fotg210) >> 3) %
+		fotg210->periodic_size;
+}
+
+/* The EHCI in ChipIdea HDRC cannot be a separate module or device,
+ * because its registers (and irq) are shared between host/gadget/otg
+ * functions  and in order to facilitate role switching we cannot
+ * give the fotg210 driver exclusive access to those.
+ */
+
+static const struct hc_driver fotg210_fotg210_hc_driver = {
+	.description		= hcd_name,
+	.product_desc		= "Faraday USB2.0 Host Controller",
+	.hcd_priv_size		= sizeof(struct fotg210_hcd),
+
+	/*
+	 * generic hardware linkage
+	 */
+	.irq			= fotg210_irq,
+	.flags			= HCD_MEMORY | HCD_DMA | HCD_USB2,
+
+	/*
+	 * basic lifecycle operations
+	 */
+	.reset			= hcd_fotg210_init,
+	.start			= fotg210_run,
+	.stop			= fotg210_stop,
+	.shutdown		= fotg210_shutdown,
+
+	/*
+	 * managing i/o requests and associated device resources
+	 */
+	.urb_enqueue		= fotg210_urb_enqueue,
+	.urb_dequeue		= fotg210_urb_dequeue,
+	.endpoint_disable	= fotg210_endpoint_disable,
+	.endpoint_reset		= fotg210_endpoint_reset,
+
+	/*
+	 * scheduling support
+	 */
+	.get_frame_number	= fotg210_get_frame,
+
+	/*
+	 * root hub support
+	 */
+	.hub_status_data	= fotg210_hub_status_data,
+	.hub_control		= fotg210_hub_control,
+	.bus_suspend		= fotg210_bus_suspend,
+	.bus_resume		= fotg210_bus_resume,
+
+	.relinquish_port	= fotg210_relinquish_port,
+	.port_handed_over	= fotg210_port_handed_over,
+
+	.clear_tt_buffer_complete = fotg210_clear_tt_buffer_complete,
+};
+
+static void fotg210_init(struct fotg210_hcd *fotg210)
+{
+	u32 value;
+
+	iowrite32(GMIR_MDEV_INT | GMIR_MOTG_INT | GMIR_INT_POLARITY,
+			&fotg210->regs->gmir);
+
+	value = ioread32(&fotg210->regs->otgcsr);
+	value &= ~OTGCSR_A_BUS_DROP;
+	value |= OTGCSR_A_BUS_REQ;
+	iowrite32(value, &fotg210->regs->otgcsr);
+}
+
+/*
+ * fotg210_hcd_probe - initialize faraday FOTG210 HCDs
+ *
+ * Allocates basic resources for this USB host controller, and
+ * then invokes the start() method for the HCD associated with it
+ * through the hotplug entry's driver_data.
+ */
+int fotg210_hcd_probe(struct platform_device *pdev, struct fotg210 *fotg)
+{
+	struct device *dev = &pdev->dev;
+	struct usb_hcd *hcd;
+	int irq;
+	int retval;
+	struct fotg210_hcd *fotg210;
+
+	if (usb_disabled())
+		return -ENODEV;
+
+	pdev->dev.power.power_state = PMSG_ON;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	hcd = usb_create_hcd(&fotg210_fotg210_hc_driver, dev,
+			dev_name(dev));
+	if (!hcd) {
+		retval = dev_err_probe(dev, -ENOMEM, "failed to create hcd\n");
+		goto fail_create_hcd;
+	}
+
+	hcd->has_tt = 1;
+
+	hcd->regs = fotg->base;
+
+	hcd->rsrc_start = fotg->res->start;
+	hcd->rsrc_len = resource_size(fotg->res);
+
+	fotg210 = hcd_to_fotg210(hcd);
+
+	fotg210->fotg = fotg;
+	fotg210->caps = hcd->regs;
+
+	retval = fotg210_setup(hcd);
+	if (retval)
+		goto failed_put_hcd;
+
+	fotg210_init(fotg210);
+
+	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
+	if (retval) {
+		dev_err_probe(dev, retval, "failed to add hcd\n");
+		goto failed_put_hcd;
+	}
+	device_wakeup_enable(hcd->self.controller);
+	platform_set_drvdata(pdev, hcd);
+
+	return retval;
+
+failed_put_hcd:
+	usb_put_hcd(hcd);
+fail_create_hcd:
+	return dev_err_probe(dev, retval, "init %s fail\n", dev_name(dev));
+}
+
+/*
+ * fotg210_hcd_remove - shutdown processing for EHCI HCDs
+ * @dev: USB Host Controller being removed
+ *
+ */
+int fotg210_hcd_remove(struct platform_device *pdev)
+{
+	struct usb_hcd *hcd = platform_get_drvdata(pdev);
+
+	usb_remove_hcd(hcd);
+	usb_put_hcd(hcd);
+
+	return 0;
+}
+
+int __init fotg210_hcd_init(void)
+{
+	if (usb_disabled())
+		return -ENODEV;
+
+	set_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
+	if (test_bit(USB_UHCI_LOADED, &usb_hcds_loaded) ||
+			test_bit(USB_OHCI_LOADED, &usb_hcds_loaded))
+		pr_warn("Warning! fotg210_hcd should always be loaded before uhci_hcd and ohci_hcd, not after\n");
+
+	pr_debug("%s: block sizes: qh %zd qtd %zd itd %zd\n",
+			hcd_name, sizeof(struct fotg210_qh),
+			sizeof(struct fotg210_qtd),
+			sizeof(struct fotg210_itd));
+
+	fotg210_debug_root = debugfs_create_dir("fotg210", usb_debug_root);
+
+	return 0;
+}
+
+void __exit fotg210_hcd_cleanup(void)
+{
+	debugfs_remove(fotg210_debug_root);
+	clear_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
+}