Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 803 insertions, 0 deletions

diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
new file mode 100644
index 000000000..90cee192e
--- /dev/null
+++ b/drivers/usb/host/ohci-hub.c
@@ -0,0 +1,803 @@
+// SPDX-License-Identifier: GPL-1.0+
+/*
+ * OHCI HCD (Host Controller Driver) for USB.
+ *
+ * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
+ * (C) Copyright 2000-2004 David Brownell <dbrownell@users.sourceforge.net>
+ *
+ * This file is licenced under GPL
+ */
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * OHCI Root Hub ... the nonsharable stuff
+ */
+
+#define dbg_port(hc,label,num,value) \
+	ohci_dbg (hc, \
+		"%s roothub.portstatus [%d] " \
+		"= 0x%08x%s%s%s%s%s%s%s%s%s%s%s%s\n", \
+		label, num, value, \
+		(value & RH_PS_PRSC) ? " PRSC" : "", \
+		(value & RH_PS_OCIC) ? " OCIC" : "", \
+		(value & RH_PS_PSSC) ? " PSSC" : "", \
+		(value & RH_PS_PESC) ? " PESC" : "", \
+		(value & RH_PS_CSC) ? " CSC" : "", \
+		\
+		(value & RH_PS_LSDA) ? " LSDA" : "", \
+		(value & RH_PS_PPS) ? " PPS" : "", \
+		(value & RH_PS_PRS) ? " PRS" : "", \
+		(value & RH_PS_POCI) ? " POCI" : "", \
+		(value & RH_PS_PSS) ? " PSS" : "", \
+		\
+		(value & RH_PS_PES) ? " PES" : "", \
+		(value & RH_PS_CCS) ? " CCS" : "" \
+		);
+
+/*-------------------------------------------------------------------------*/
+
+#define OHCI_SCHED_ENABLES \
+	(OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE)
+
+static void update_done_list(struct ohci_hcd *);
+static void ohci_work(struct ohci_hcd *);
+
+#ifdef	CONFIG_PM
+static int ohci_rh_suspend (struct ohci_hcd *ohci, int autostop)
+__releases(ohci->lock)
+__acquires(ohci->lock)
+{
+	int			status = 0;
+
+	ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
+	switch (ohci->hc_control & OHCI_CTRL_HCFS) {
+	case OHCI_USB_RESUME:
+		ohci_dbg (ohci, "resume/suspend?\n");
+		ohci->hc_control &= ~OHCI_CTRL_HCFS;
+		ohci->hc_control |= OHCI_USB_RESET;
+		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
+		(void) ohci_readl (ohci, &ohci->regs->control);
+		fallthrough;
+	case OHCI_USB_RESET:
+		status = -EBUSY;
+		ohci_dbg (ohci, "needs reinit!\n");
+		goto done;
+	case OHCI_USB_SUSPEND:
+		if (!ohci->autostop) {
+			ohci_dbg (ohci, "already suspended\n");
+			goto done;
+		}
+	}
+	ohci_dbg (ohci, "%s root hub\n",
+			autostop ? "auto-stop" : "suspend");
+
+	/* First stop any processing */
+	if (!autostop && (ohci->hc_control & OHCI_SCHED_ENABLES)) {
+		ohci->hc_control &= ~OHCI_SCHED_ENABLES;
+		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
+		ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
+		ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
+
+		/* sched disables take effect on the next frame,
+		 * then the last WDH could take 6+ msec
+		 */
+		ohci_dbg (ohci, "stopping schedules ...\n");
+		ohci->autostop = 0;
+		spin_unlock_irq (&ohci->lock);
+		msleep (8);
+		spin_lock_irq (&ohci->lock);
+	}
+	update_done_list(ohci);
+	ohci_work(ohci);
+
+	/* All ED unlinks should be finished, no need for SOF interrupts */
+	ohci_writel(ohci, OHCI_INTR_SF, &ohci->regs->intrdisable);
+
+	/*
+	 * Some controllers don't handle "global" suspend properly if
+	 * there are unsuspended ports.  For these controllers, put all
+	 * the enabled ports into suspend before suspending the root hub.
+	 */
+	if (ohci->flags & OHCI_QUIRK_GLOBAL_SUSPEND) {
+		__hc32 __iomem	*portstat = ohci->regs->roothub.portstatus;
+		int		i;
+		unsigned	temp;
+
+		for (i = 0; i < ohci->num_ports; (++i, ++portstat)) {
+			temp = ohci_readl(ohci, portstat);
+			if ((temp & (RH_PS_PES | RH_PS_PSS)) ==
+					RH_PS_PES)
+				ohci_writel(ohci, RH_PS_PSS, portstat);
+		}
+	}
+
+	/* maybe resume can wake root hub */
+	if (ohci_to_hcd(ohci)->self.root_hub->do_remote_wakeup || autostop) {
+		ohci->hc_control |= OHCI_CTRL_RWE;
+	} else {
+		ohci_writel(ohci, OHCI_INTR_RHSC | OHCI_INTR_RD,
+				&ohci->regs->intrdisable);
+		ohci->hc_control &= ~OHCI_CTRL_RWE;
+	}
+
+	/* Suspend hub ... this is the "global (to this bus) suspend" mode,
+	 * which doesn't imply ports will first be individually suspended.
+	 */
+	ohci->hc_control &= ~OHCI_CTRL_HCFS;
+	ohci->hc_control |= OHCI_USB_SUSPEND;
+	ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
+	(void) ohci_readl (ohci, &ohci->regs->control);
+
+	/* no resumes until devices finish suspending */
+	if (!autostop) {
+		ohci->next_statechange = jiffies + msecs_to_jiffies (5);
+		ohci->autostop = 0;
+		ohci->rh_state = OHCI_RH_SUSPENDED;
+	}
+
+done:
+	return status;
+}
+
+static inline struct ed *find_head (struct ed *ed)
+{
+	/* for bulk and control lists */
+	while (ed->ed_prev)
+		ed = ed->ed_prev;
+	return ed;
+}
+
+/* caller has locked the root hub */
+static int ohci_rh_resume (struct ohci_hcd *ohci)
+__releases(ohci->lock)
+__acquires(ohci->lock)
+{
+	struct usb_hcd		*hcd = ohci_to_hcd (ohci);
+	u32			temp, enables;
+	int			status = -EINPROGRESS;
+	int			autostopped = ohci->autostop;
+
+	ohci->autostop = 0;
+	ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
+
+	if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
+		/* this can happen after resuming a swsusp snapshot */
+		if (ohci->rh_state != OHCI_RH_RUNNING) {
+			ohci_dbg (ohci, "BIOS/SMM active, control %03x\n",
+					ohci->hc_control);
+			status = -EBUSY;
+		/* this happens when pmcore resumes HC then root */
+		} else {
+			ohci_dbg (ohci, "duplicate resume\n");
+			status = 0;
+		}
+	} else switch (ohci->hc_control & OHCI_CTRL_HCFS) {
+	case OHCI_USB_SUSPEND:
+		ohci->hc_control &= ~(OHCI_CTRL_HCFS|OHCI_SCHED_ENABLES);
+		ohci->hc_control |= OHCI_USB_RESUME;
+		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
+		(void) ohci_readl (ohci, &ohci->regs->control);
+		ohci_dbg (ohci, "%s root hub\n",
+				autostopped ? "auto-start" : "resume");
+		break;
+	case OHCI_USB_RESUME:
+		/* HCFS changes sometime after INTR_RD */
+		ohci_dbg(ohci, "%swakeup root hub\n",
+				autostopped ? "auto-" : "");
+		break;
+	case OHCI_USB_OPER:
+		/* this can happen after resuming a swsusp snapshot */
+		ohci_dbg (ohci, "snapshot resume? reinit\n");
+		status = -EBUSY;
+		break;
+	default:		/* RESET, we lost power */
+		ohci_dbg (ohci, "lost power\n");
+		status = -EBUSY;
+	}
+	if (status == -EBUSY) {
+		if (!autostopped) {
+			spin_unlock_irq (&ohci->lock);
+			status = ohci_restart (ohci);
+
+			usb_root_hub_lost_power(hcd->self.root_hub);
+
+			spin_lock_irq (&ohci->lock);
+		}
+		return status;
+	}
+	if (status != -EINPROGRESS)
+		return status;
+	if (autostopped)
+		goto skip_resume;
+	spin_unlock_irq (&ohci->lock);
+
+	/* Some controllers (lucent erratum) need extra-long delays */
+	msleep (20 /* usb 11.5.1.10 */ + 12 /* 32 msec counter */ + 1);
+
+	temp = ohci_readl (ohci, &ohci->regs->control);
+	temp &= OHCI_CTRL_HCFS;
+	if (temp != OHCI_USB_RESUME) {
+		ohci_err (ohci, "controller won't resume\n");
+		spin_lock_irq(&ohci->lock);
+		return -EBUSY;
+	}
+
+	/* disable old schedule state, reinit from scratch */
+	ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
+	ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
+	ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);
+	ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
+	ohci_writel (ohci, 0, &ohci->regs->ed_periodcurrent);
+	ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);
+
+	/* Sometimes PCI D3 suspend trashes frame timings ... */
+	periodic_reinit (ohci);
+
+	/*
+	 * The following code is executed with ohci->lock held and
+	 * irqs disabled if and only if autostopped is true.  This
+	 * will cause sparse to warn about a "context imbalance".
+	 */
+skip_resume:
+	/* interrupts might have been disabled */
+	ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
+	if (ohci->ed_rm_list)
+		ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
+
+	/* Then re-enable operations */
+	ohci_writel (ohci, OHCI_USB_OPER, &ohci->regs->control);
+	(void) ohci_readl (ohci, &ohci->regs->control);
+	if (!autostopped)
+		msleep (3);
+
+	temp = ohci->hc_control;
+	temp &= OHCI_CTRL_RWC;
+	temp |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
+	ohci->hc_control = temp;
+	ohci_writel (ohci, temp, &ohci->regs->control);
+	(void) ohci_readl (ohci, &ohci->regs->control);
+
+	/* TRSMRCY */
+	if (!autostopped) {
+		msleep (10);
+		spin_lock_irq (&ohci->lock);
+	}
+	/* now ohci->lock is always held and irqs are always disabled */
+
+	/* keep it alive for more than ~5x suspend + resume costs */
+	ohci->next_statechange = jiffies + STATECHANGE_DELAY;
+
+	/* maybe turn schedules back on */
+	enables = 0;
+	temp = 0;
+	if (!ohci->ed_rm_list) {
+		if (ohci->ed_controltail) {
+			ohci_writel (ohci,
+					find_head (ohci->ed_controltail)->dma,
+					&ohci->regs->ed_controlhead);
+			enables |= OHCI_CTRL_CLE;
+			temp |= OHCI_CLF;
+		}
+		if (ohci->ed_bulktail) {
+			ohci_writel (ohci, find_head (ohci->ed_bulktail)->dma,
+				&ohci->regs->ed_bulkhead);
+			enables |= OHCI_CTRL_BLE;
+			temp |= OHCI_BLF;
+		}
+	}
+	if (hcd->self.bandwidth_isoc_reqs || hcd->self.bandwidth_int_reqs)
+		enables |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
+	if (enables) {
+		ohci_dbg (ohci, "restarting schedules ... %08x\n", enables);
+		ohci->hc_control |= enables;
+		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
+		if (temp)
+			ohci_writel (ohci, temp, &ohci->regs->cmdstatus);
+		(void) ohci_readl (ohci, &ohci->regs->control);
+	}
+
+	ohci->rh_state = OHCI_RH_RUNNING;
+	return 0;
+}
+
+static int ohci_bus_suspend (struct usb_hcd *hcd)
+{
+	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
+	int			rc;
+
+	spin_lock_irq (&ohci->lock);
+
+	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
+		rc = -ESHUTDOWN;
+	else
+		rc = ohci_rh_suspend (ohci, 0);
+	spin_unlock_irq (&ohci->lock);
+
+	if (rc == 0) {
+		del_timer_sync(&ohci->io_watchdog);
+		ohci->prev_frame_no = IO_WATCHDOG_OFF;
+	}
+	return rc;
+}
+
+static int ohci_bus_resume (struct usb_hcd *hcd)
+{
+	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
+	int			rc;
+
+	if (time_before (jiffies, ohci->next_statechange))
+		msleep(5);
+
+	spin_lock_irq (&ohci->lock);
+
+	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
+		rc = -ESHUTDOWN;
+	else
+		rc = ohci_rh_resume (ohci);
+	spin_unlock_irq (&ohci->lock);
+
+	/* poll until we know a device is connected or we autostop */
+	if (rc == 0)
+		usb_hcd_poll_rh_status(hcd);
+	return rc;
+}
+
+/* Carry out polling-, autostop-, and autoresume-related state changes */
+static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
+		int any_connected, int rhsc_status)
+{
+	int	poll_rh = 1;
+	int	rhsc_enable;
+
+	/* Some broken controllers never turn off RHSC in the interrupt
+	 * status register.  For their sake we won't re-enable RHSC
+	 * interrupts if the interrupt bit is already active.
+	 */
+	rhsc_enable = ohci_readl(ohci, &ohci->regs->intrenable) &
+			OHCI_INTR_RHSC;
+
+	switch (ohci->hc_control & OHCI_CTRL_HCFS) {
+	case OHCI_USB_OPER:
+		/* If no status changes are pending, enable RHSC interrupts. */
+		if (!rhsc_enable && !rhsc_status && !changed) {
+			rhsc_enable = OHCI_INTR_RHSC;
+			ohci_writel(ohci, rhsc_enable, &ohci->regs->intrenable);
+		}
+
+		/* Keep on polling until we know a device is connected
+		 * and RHSC is enabled, or until we autostop.
+		 */
+		if (!ohci->autostop) {
+			if (any_connected ||
+					!device_may_wakeup(&ohci_to_hcd(ohci)
+						->self.root_hub->dev)) {
+				if (rhsc_enable)
+					poll_rh = 0;
+			} else {
+				ohci->autostop = 1;
+				ohci->next_statechange = jiffies + HZ;
+			}
+
+		/* if no devices have been attached for one second, autostop */
+		} else {
+			if (changed || any_connected) {
+				ohci->autostop = 0;
+				ohci->next_statechange = jiffies +
+						STATECHANGE_DELAY;
+			} else if (time_after_eq(jiffies,
+						ohci->next_statechange)
+					&& !ohci->ed_rm_list
+					&& !(ohci->hc_control &
+						OHCI_SCHED_ENABLES)) {
+				ohci_rh_suspend(ohci, 1);
+				if (rhsc_enable)
+					poll_rh = 0;
+			}
+		}
+		break;
+
+	case OHCI_USB_SUSPEND:
+	case OHCI_USB_RESUME:
+		/* if there is a port change, autostart or ask to be resumed */
+		if (changed) {
+			if (ohci->autostop)
+				ohci_rh_resume(ohci);
+			else
+				usb_hcd_resume_root_hub(ohci_to_hcd(ohci));
+
+		/* If remote wakeup is disabled, stop polling */
+		} else if (!ohci->autostop &&
+				!ohci_to_hcd(ohci)->self.root_hub->
+					do_remote_wakeup) {
+			poll_rh = 0;
+
+		} else {
+			/* If no status changes are pending,
+			 * enable RHSC interrupts
+			 */
+			if (!rhsc_enable && !rhsc_status) {
+				rhsc_enable = OHCI_INTR_RHSC;
+				ohci_writel(ohci, rhsc_enable,
+						&ohci->regs->intrenable);
+			}
+			/* Keep polling until RHSC is enabled */
+			if (rhsc_enable)
+				poll_rh = 0;
+		}
+		break;
+	}
+	return poll_rh;
+}
+
+#else	/* CONFIG_PM */
+
+static inline int ohci_rh_resume(struct ohci_hcd *ohci)
+{
+	return 0;
+}
+
+/* Carry out polling-related state changes.
+ * autostop isn't used when CONFIG_PM is turned off.
+ */
+static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
+		int any_connected, int rhsc_status)
+{
+	/* If RHSC is enabled, don't poll */
+	if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
+		return 0;
+
+	/* If status changes are pending, continue polling.
+	 * Conversely, if no status changes are pending but the RHSC
+	 * status bit was set, then RHSC may be broken so continue polling.
+	 */
+	if (changed || rhsc_status)
+		return 1;
+
+	/* It's safe to re-enable RHSC interrupts */
+	ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
+	return 0;
+}
+
+#endif	/* CONFIG_PM */
+
+/*-------------------------------------------------------------------------*/
+
+/* build "status change" packet (one or two bytes) from HC registers */
+
+int ohci_hub_status_data(struct usb_hcd *hcd, char *buf)
+{
+	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
+	int		i, changed = 0, length = 1;
+	int		any_connected = 0;
+	int		rhsc_status;
+	unsigned long	flags;
+
+	spin_lock_irqsave (&ohci->lock, flags);
+	if (!HCD_HW_ACCESSIBLE(hcd))
+		goto done;
+
+	/* undocumented erratum seen on at least rev D */
+	if ((ohci->flags & OHCI_QUIRK_AMD756)
+			&& (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
+		ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
+			  ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
+		/* retry later; "should not happen" */
+		goto done;
+	}
+
+	/* init status */
+	if (roothub_status (ohci) & (RH_HS_LPSC | RH_HS_OCIC))
+		buf [0] = changed = 1;
+	else
+		buf [0] = 0;
+	if (ohci->num_ports > 7) {
+		buf [1] = 0;
+		length++;
+	}
+
+	/* Clear the RHSC status flag before reading the port statuses */
+	ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrstatus);
+	rhsc_status = ohci_readl(ohci, &ohci->regs->intrstatus) &
+			OHCI_INTR_RHSC;
+
+	/* look at each port */
+	for (i = 0; i < ohci->num_ports; i++) {
+		u32	status = roothub_portstatus (ohci, i);
+
+		/* can't autostop if ports are connected */
+		any_connected |= (status & RH_PS_CCS);
+
+		if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
+				| RH_PS_OCIC | RH_PS_PRSC)) {
+			changed = 1;
+			if (i < 7)
+			    buf [0] |= 1 << (i + 1);
+			else
+			    buf [1] |= 1 << (i - 7);
+		}
+	}
+
+	if (ohci_root_hub_state_changes(ohci, changed,
+			any_connected, rhsc_status))
+		set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
+	else
+		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
+
+
+done:
+	spin_unlock_irqrestore (&ohci->lock, flags);
+
+	return changed ? length : 0;
+}
+EXPORT_SYMBOL_GPL(ohci_hub_status_data);
+
+/*-------------------------------------------------------------------------*/
+
+static void
+ohci_hub_descriptor (
+	struct ohci_hcd			*ohci,
+	struct usb_hub_descriptor	*desc
+) {
+	u32		rh = roothub_a (ohci);
+	u16		temp;
+
+	desc->bDescriptorType = USB_DT_HUB;
+	desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
+	desc->bHubContrCurrent = 0;
+
+	desc->bNbrPorts = ohci->num_ports;
+	temp = 1 + (ohci->num_ports / 8);
+	desc->bDescLength = 7 + 2 * temp;
+
+	temp = HUB_CHAR_COMMON_LPSM | HUB_CHAR_COMMON_OCPM;
+	if (rh & RH_A_NPS)		/* no power switching? */
+		temp |= HUB_CHAR_NO_LPSM;
+	if (rh & RH_A_PSM)		/* per-port power switching? */
+		temp |= HUB_CHAR_INDV_PORT_LPSM;
+	if (rh & RH_A_NOCP)		/* no overcurrent reporting? */
+		temp |= HUB_CHAR_NO_OCPM;
+	else if (rh & RH_A_OCPM)	/* per-port overcurrent reporting? */
+		temp |= HUB_CHAR_INDV_PORT_OCPM;
+	desc->wHubCharacteristics = cpu_to_le16(temp);
+
+	/* ports removable, and usb 1.0 legacy PortPwrCtrlMask */
+	rh = roothub_b (ohci);
+	memset(desc->u.hs.DeviceRemovable, 0xff,
+			sizeof(desc->u.hs.DeviceRemovable));
+	desc->u.hs.DeviceRemovable[0] = rh & RH_B_DR;
+	if (ohci->num_ports > 7) {
+		desc->u.hs.DeviceRemovable[1] = (rh & RH_B_DR) >> 8;
+		desc->u.hs.DeviceRemovable[2] = 0xff;
+	} else
+		desc->u.hs.DeviceRemovable[1] = 0xff;
+}
+
+/*-------------------------------------------------------------------------*/
+
+#ifdef	CONFIG_USB_OTG
+
+static int ohci_start_port_reset (struct usb_hcd *hcd, unsigned port)
+{
+	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
+	u32			status;
+
+	if (!port)
+		return -EINVAL;
+	port--;
+
+	/* start port reset before HNP protocol times out */
+	status = ohci_readl(ohci, &ohci->regs->roothub.portstatus [port]);
+	if (!(status & RH_PS_CCS))
+		return -ENODEV;
+
+	/* hub_wq will finish the reset later */
+	ohci_writel(ohci, RH_PS_PRS, &ohci->regs->roothub.portstatus [port]);
+	return 0;
+}
+
+#else
+
+#define	ohci_start_port_reset		NULL
+
+#endif
+
+/*-------------------------------------------------------------------------*/
+
+
+/* See usb 7.1.7.5:  root hubs must issue at least 50 msec reset signaling,
+ * not necessarily continuous ... to guard against resume signaling.
+ */
+#define	PORT_RESET_MSEC		50
+
+/* this timer value might be vendor-specific ... */
+#define	PORT_RESET_HW_MSEC	10
+
+/* wrap-aware logic morphed from <linux/jiffies.h> */
+#define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0)
+
+/* called from some task, normally hub_wq */
+static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
+{
+	__hc32 __iomem *portstat = &ohci->regs->roothub.portstatus [port];
+	u32	temp = 0;
+	u16	now = ohci_readl(ohci, &ohci->regs->fmnumber);
+	u16	reset_done = now + PORT_RESET_MSEC;
+	int	limit_1 = DIV_ROUND_UP(PORT_RESET_MSEC, PORT_RESET_HW_MSEC);
+
+	/* build a "continuous enough" reset signal, with up to
+	 * 3msec gap between pulses.  scheduler HZ==100 must work;
+	 * this might need to be deadline-scheduled.
+	 */
+	do {
+		int limit_2;
+
+		/* spin until any current reset finishes */
+		limit_2 = PORT_RESET_HW_MSEC * 2;
+		while (--limit_2 >= 0) {
+			temp = ohci_readl (ohci, portstat);
+			/* handle e.g. CardBus eject */
+			if (temp == ~(u32)0)
+				return -ESHUTDOWN;
+			if (!(temp & RH_PS_PRS))
+				break;
+			udelay (500);
+		}
+
+		/* timeout (a hardware error) has been observed when
+		 * EHCI sets CF while this driver is resetting a port;
+		 * presumably other disconnect paths might do it too.
+		 */
+		if (limit_2 < 0) {
+			ohci_dbg(ohci,
+				"port[%d] reset timeout, stat %08x\n",
+				port, temp);
+			break;
+		}
+
+		if (!(temp & RH_PS_CCS))
+			break;
+		if (temp & RH_PS_PRSC)
+			ohci_writel (ohci, RH_PS_PRSC, portstat);
+
+		/* start the next reset, sleep till it's probably done */
+		ohci_writel (ohci, RH_PS_PRS, portstat);
+		msleep(PORT_RESET_HW_MSEC);
+		now = ohci_readl(ohci, &ohci->regs->fmnumber);
+	} while (tick_before(now, reset_done) && --limit_1 >= 0);
+
+	/* caller synchronizes using PRSC ... and handles PRS
+	 * still being set when this returns.
+	 */
+
+	return 0;
+}
+
+int ohci_hub_control(
+	struct usb_hcd	*hcd,
+	u16		typeReq,
+	u16		wValue,
+	u16		wIndex,
+	char		*buf,
+	u16		wLength
+) {
+	struct ohci_hcd	*ohci = hcd_to_ohci (hcd);
+	int		ports = ohci->num_ports;
+	u32		temp;
+	int		retval = 0;
+
+	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
+		return -ESHUTDOWN;
+
+	switch (typeReq) {
+	case ClearHubFeature:
+		switch (wValue) {
+		case C_HUB_OVER_CURRENT:
+			ohci_writel (ohci, RH_HS_OCIC,
+					&ohci->regs->roothub.status);
+			break;
+		case C_HUB_LOCAL_POWER:
+			break;
+		default:
+			goto error;
+		}
+		break;
+	case ClearPortFeature:
+		if (!wIndex || wIndex > ports)
+			goto error;
+		wIndex--;
+
+		switch (wValue) {
+		case USB_PORT_FEAT_ENABLE:
+			temp = RH_PS_CCS;
+			break;
+		case USB_PORT_FEAT_C_ENABLE:
+			temp = RH_PS_PESC;
+			break;
+		case USB_PORT_FEAT_SUSPEND:
+			temp = RH_PS_POCI;
+			break;
+		case USB_PORT_FEAT_C_SUSPEND:
+			temp = RH_PS_PSSC;
+			break;
+		case USB_PORT_FEAT_POWER:
+			temp = RH_PS_LSDA;
+			break;
+		case USB_PORT_FEAT_C_CONNECTION:
+			temp = RH_PS_CSC;
+			break;
+		case USB_PORT_FEAT_C_OVER_CURRENT:
+			temp = RH_PS_OCIC;
+			break;
+		case USB_PORT_FEAT_C_RESET:
+			temp = RH_PS_PRSC;
+			break;
+		default:
+			goto error;
+		}
+		ohci_writel (ohci, temp,
+				&ohci->regs->roothub.portstatus [wIndex]);
+		// ohci_readl (ohci, &ohci->regs->roothub.portstatus [wIndex]);
+		break;
+	case GetHubDescriptor:
+		ohci_hub_descriptor (ohci, (struct usb_hub_descriptor *) buf);
+		break;
+	case GetHubStatus:
+		temp = roothub_status (ohci) & ~(RH_HS_CRWE | RH_HS_DRWE);
+		put_unaligned_le32(temp, buf);
+		break;
+	case GetPortStatus:
+		if (!wIndex || wIndex > ports)
+			goto error;
+		wIndex--;
+		temp = roothub_portstatus (ohci, wIndex);
+		put_unaligned_le32(temp, buf);
+
+		if (*(u16*)(buf+2))	/* only if wPortChange is interesting */
+			dbg_port(ohci, "GetStatus", wIndex, temp);
+		break;
+	case SetHubFeature:
+		switch (wValue) {
+		case C_HUB_OVER_CURRENT:
+			// FIXME:  this can be cleared, yes?
+		case C_HUB_LOCAL_POWER:
+			break;
+		default:
+			goto error;
+		}
+		break;
+	case SetPortFeature:
+		if (!wIndex || wIndex > ports)
+			goto error;
+		wIndex--;
+		switch (wValue) {
+		case USB_PORT_FEAT_SUSPEND:
+#ifdef	CONFIG_USB_OTG
+			if (hcd->self.otg_port == (wIndex + 1)
+					&& hcd->self.b_hnp_enable)
+				ohci->start_hnp(ohci);
+			else
+#endif
+			ohci_writel (ohci, RH_PS_PSS,
+				&ohci->regs->roothub.portstatus [wIndex]);
+			break;
+		case USB_PORT_FEAT_POWER:
+			ohci_writel (ohci, RH_PS_PPS,
+				&ohci->regs->roothub.portstatus [wIndex]);
+			break;
+		case USB_PORT_FEAT_RESET:
+			retval = root_port_reset (ohci, wIndex);
+			break;
+		default:
+			goto error;
+		}
+		break;
+
+	default:
+error:
+		/* "protocol stall" on error */
+		retval = -EPIPE;
+	}
+	return retval;
+}
+EXPORT_SYMBOL_GPL(ohci_hub_control);