Adding upstream version 5.10.209.upstream/5.10.209

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

1 files changed, 1793 insertions, 0 deletions

diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c
new file mode 100644
index 000000000..35fcb8261
--- /dev/null
+++ b/drivers/usb/host/uhci-q.c
@@ -0,0 +1,1793 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Universal Host Controller Interface driver for USB.
+ *
+ * Maintainer: Alan Stern <stern@rowland.harvard.edu>
+ *
+ * (C) Copyright 1999 Linus Torvalds
+ * (C) Copyright 1999-2002 Johannes Erdfelt, johannes@erdfelt.com
+ * (C) Copyright 1999 Randy Dunlap
+ * (C) Copyright 1999 Georg Acher, acher@in.tum.de
+ * (C) Copyright 1999 Deti Fliegl, deti@fliegl.de
+ * (C) Copyright 1999 Thomas Sailer, sailer@ife.ee.ethz.ch
+ * (C) Copyright 1999 Roman Weissgaerber, weissg@vienna.at
+ * (C) Copyright 2000 Yggdrasil Computing, Inc. (port of new PCI interface
+ *               support from usb-ohci.c by Adam Richter, adam@yggdrasil.com).
+ * (C) Copyright 1999 Gregory P. Smith (from usb-ohci.c)
+ * (C) Copyright 2004-2007 Alan Stern, stern@rowland.harvard.edu
+ */
+
+
+/*
+ * Technically, updating td->status here is a race, but it's not really a
+ * problem. The worst that can happen is that we set the IOC bit again
+ * generating a spurious interrupt. We could fix this by creating another
+ * QH and leaving the IOC bit always set, but then we would have to play
+ * games with the FSBR code to make sure we get the correct order in all
+ * the cases. I don't think it's worth the effort
+ */
+static void uhci_set_next_interrupt(struct uhci_hcd *uhci)
+{
+	if (uhci->is_stopped)
+		mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
+	uhci->term_td->status |= cpu_to_hc32(uhci, TD_CTRL_IOC);
+}
+
+static inline void uhci_clear_next_interrupt(struct uhci_hcd *uhci)
+{
+	uhci->term_td->status &= ~cpu_to_hc32(uhci, TD_CTRL_IOC);
+}
+
+
+/*
+ * Full-Speed Bandwidth Reclamation (FSBR).
+ * We turn on FSBR whenever a queue that wants it is advancing,
+ * and leave it on for a short time thereafter.
+ */
+static void uhci_fsbr_on(struct uhci_hcd *uhci)
+{
+	struct uhci_qh *lqh;
+
+	/* The terminating skeleton QH always points back to the first
+	 * FSBR QH.  Make the last async QH point to the terminating
+	 * skeleton QH. */
+	uhci->fsbr_is_on = 1;
+	lqh = list_entry(uhci->skel_async_qh->node.prev,
+			struct uhci_qh, node);
+	lqh->link = LINK_TO_QH(uhci, uhci->skel_term_qh);
+}
+
+static void uhci_fsbr_off(struct uhci_hcd *uhci)
+{
+	struct uhci_qh *lqh;
+
+	/* Remove the link from the last async QH to the terminating
+	 * skeleton QH. */
+	uhci->fsbr_is_on = 0;
+	lqh = list_entry(uhci->skel_async_qh->node.prev,
+			struct uhci_qh, node);
+	lqh->link = UHCI_PTR_TERM(uhci);
+}
+
+static void uhci_add_fsbr(struct uhci_hcd *uhci, struct urb *urb)
+{
+	struct urb_priv *urbp = urb->hcpriv;
+
+	urbp->fsbr = 1;
+}
+
+static void uhci_urbp_wants_fsbr(struct uhci_hcd *uhci, struct urb_priv *urbp)
+{
+	if (urbp->fsbr) {
+		uhci->fsbr_is_wanted = 1;
+		if (!uhci->fsbr_is_on)
+			uhci_fsbr_on(uhci);
+		else if (uhci->fsbr_expiring) {
+			uhci->fsbr_expiring = 0;
+			del_timer(&uhci->fsbr_timer);
+		}
+	}
+}
+
+static void uhci_fsbr_timeout(struct timer_list *t)
+{
+	struct uhci_hcd *uhci = from_timer(uhci, t, fsbr_timer);
+	unsigned long flags;
+
+	spin_lock_irqsave(&uhci->lock, flags);
+	if (uhci->fsbr_expiring) {
+		uhci->fsbr_expiring = 0;
+		uhci_fsbr_off(uhci);
+	}
+	spin_unlock_irqrestore(&uhci->lock, flags);
+}
+
+
+static struct uhci_td *uhci_alloc_td(struct uhci_hcd *uhci)
+{
+	dma_addr_t dma_handle;
+	struct uhci_td *td;
+
+	td = dma_pool_alloc(uhci->td_pool, GFP_ATOMIC, &dma_handle);
+	if (!td)
+		return NULL;
+
+	td->dma_handle = dma_handle;
+	td->frame = -1;
+
+	INIT_LIST_HEAD(&td->list);
+	INIT_LIST_HEAD(&td->fl_list);
+
+	return td;
+}
+
+static void uhci_free_td(struct uhci_hcd *uhci, struct uhci_td *td)
+{
+	if (!list_empty(&td->list))
+		dev_WARN(uhci_dev(uhci), "td %p still in list!\n", td);
+	if (!list_empty(&td->fl_list))
+		dev_WARN(uhci_dev(uhci), "td %p still in fl_list!\n", td);
+
+	dma_pool_free(uhci->td_pool, td, td->dma_handle);
+}
+
+static inline void uhci_fill_td(struct uhci_hcd *uhci, struct uhci_td *td,
+		u32 status, u32 token, u32 buffer)
+{
+	td->status = cpu_to_hc32(uhci, status);
+	td->token = cpu_to_hc32(uhci, token);
+	td->buffer = cpu_to_hc32(uhci, buffer);
+}
+
+static void uhci_add_td_to_urbp(struct uhci_td *td, struct urb_priv *urbp)
+{
+	list_add_tail(&td->list, &urbp->td_list);
+}
+
+static void uhci_remove_td_from_urbp(struct uhci_td *td)
+{
+	list_del_init(&td->list);
+}
+
+/*
+ * We insert Isochronous URBs directly into the frame list at the beginning
+ */
+static inline void uhci_insert_td_in_frame_list(struct uhci_hcd *uhci,
+		struct uhci_td *td, unsigned framenum)
+{
+	framenum &= (UHCI_NUMFRAMES - 1);
+
+	td->frame = framenum;
+
+	/* Is there a TD already mapped there? */
+	if (uhci->frame_cpu[framenum]) {
+		struct uhci_td *ftd, *ltd;
+
+		ftd = uhci->frame_cpu[framenum];
+		ltd = list_entry(ftd->fl_list.prev, struct uhci_td, fl_list);
+
+		list_add_tail(&td->fl_list, &ftd->fl_list);
+
+		td->link = ltd->link;
+		wmb();
+		ltd->link = LINK_TO_TD(uhci, td);
+	} else {
+		td->link = uhci->frame[framenum];
+		wmb();
+		uhci->frame[framenum] = LINK_TO_TD(uhci, td);
+		uhci->frame_cpu[framenum] = td;
+	}
+}
+
+static inline void uhci_remove_td_from_frame_list(struct uhci_hcd *uhci,
+		struct uhci_td *td)
+{
+	/* If it's not inserted, don't remove it */
+	if (td->frame == -1) {
+		WARN_ON(!list_empty(&td->fl_list));
+		return;
+	}
+
+	if (uhci->frame_cpu[td->frame] == td) {
+		if (list_empty(&td->fl_list)) {
+			uhci->frame[td->frame] = td->link;
+			uhci->frame_cpu[td->frame] = NULL;
+		} else {
+			struct uhci_td *ntd;
+
+			ntd = list_entry(td->fl_list.next,
+					 struct uhci_td,
+					 fl_list);
+			uhci->frame[td->frame] = LINK_TO_TD(uhci, ntd);
+			uhci->frame_cpu[td->frame] = ntd;
+		}
+	} else {
+		struct uhci_td *ptd;
+
+		ptd = list_entry(td->fl_list.prev, struct uhci_td, fl_list);
+		ptd->link = td->link;
+	}
+
+	list_del_init(&td->fl_list);
+	td->frame = -1;
+}
+
+static inline void uhci_remove_tds_from_frame(struct uhci_hcd *uhci,
+		unsigned int framenum)
+{
+	struct uhci_td *ftd, *ltd;
+
+	framenum &= (UHCI_NUMFRAMES - 1);
+
+	ftd = uhci->frame_cpu[framenum];
+	if (ftd) {
+		ltd = list_entry(ftd->fl_list.prev, struct uhci_td, fl_list);
+		uhci->frame[framenum] = ltd->link;
+		uhci->frame_cpu[framenum] = NULL;
+
+		while (!list_empty(&ftd->fl_list))
+			list_del_init(ftd->fl_list.prev);
+	}
+}
+
+/*
+ * Remove all the TDs for an Isochronous URB from the frame list
+ */
+static void uhci_unlink_isochronous_tds(struct uhci_hcd *uhci, struct urb *urb)
+{
+	struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
+	struct uhci_td *td;
+
+	list_for_each_entry(td, &urbp->td_list, list)
+		uhci_remove_td_from_frame_list(uhci, td);
+}
+
+static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci,
+		struct usb_device *udev, struct usb_host_endpoint *hep)
+{
+	dma_addr_t dma_handle;
+	struct uhci_qh *qh;
+
+	qh = dma_pool_zalloc(uhci->qh_pool, GFP_ATOMIC, &dma_handle);
+	if (!qh)
+		return NULL;
+
+	qh->dma_handle = dma_handle;
+
+	qh->element = UHCI_PTR_TERM(uhci);
+	qh->link = UHCI_PTR_TERM(uhci);
+
+	INIT_LIST_HEAD(&qh->queue);
+	INIT_LIST_HEAD(&qh->node);
+
+	if (udev) {		/* Normal QH */
+		qh->type = usb_endpoint_type(&hep->desc);
+		if (qh->type != USB_ENDPOINT_XFER_ISOC) {
+			qh->dummy_td = uhci_alloc_td(uhci);
+			if (!qh->dummy_td) {
+				dma_pool_free(uhci->qh_pool, qh, dma_handle);
+				return NULL;
+			}
+		}
+		qh->state = QH_STATE_IDLE;
+		qh->hep = hep;
+		qh->udev = udev;
+		hep->hcpriv = qh;
+
+		if (qh->type == USB_ENDPOINT_XFER_INT ||
+				qh->type == USB_ENDPOINT_XFER_ISOC)
+			qh->load = usb_calc_bus_time(udev->speed,
+					usb_endpoint_dir_in(&hep->desc),
+					qh->type == USB_ENDPOINT_XFER_ISOC,
+					usb_endpoint_maxp(&hep->desc))
+				/ 1000 + 1;
+
+	} else {		/* Skeleton QH */
+		qh->state = QH_STATE_ACTIVE;
+		qh->type = -1;
+	}
+	return qh;
+}
+
+static void uhci_free_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	WARN_ON(qh->state != QH_STATE_IDLE && qh->udev);
+	if (!list_empty(&qh->queue))
+		dev_WARN(uhci_dev(uhci), "qh %p list not empty!\n", qh);
+
+	list_del(&qh->node);
+	if (qh->udev) {
+		qh->hep->hcpriv = NULL;
+		if (qh->dummy_td)
+			uhci_free_td(uhci, qh->dummy_td);
+	}
+	dma_pool_free(uhci->qh_pool, qh, qh->dma_handle);
+}
+
+/*
+ * When a queue is stopped and a dequeued URB is given back, adjust
+ * the previous TD link (if the URB isn't first on the queue) or
+ * save its toggle value (if it is first and is currently executing).
+ *
+ * Returns 0 if the URB should not yet be given back, 1 otherwise.
+ */
+static int uhci_cleanup_queue(struct uhci_hcd *uhci, struct uhci_qh *qh,
+		struct urb *urb)
+{
+	struct urb_priv *urbp = urb->hcpriv;
+	struct uhci_td *td;
+	int ret = 1;
+
+	/* Isochronous pipes don't use toggles and their TD link pointers
+	 * get adjusted during uhci_urb_dequeue().  But since their queues
+	 * cannot truly be stopped, we have to watch out for dequeues
+	 * occurring after the nominal unlink frame. */
+	if (qh->type == USB_ENDPOINT_XFER_ISOC) {
+		ret = (uhci->frame_number + uhci->is_stopped !=
+				qh->unlink_frame);
+		goto done;
+	}
+
+	/* If the URB isn't first on its queue, adjust the link pointer
+	 * of the last TD in the previous URB.  The toggle doesn't need
+	 * to be saved since this URB can't be executing yet. */
+	if (qh->queue.next != &urbp->node) {
+		struct urb_priv *purbp;
+		struct uhci_td *ptd;
+
+		purbp = list_entry(urbp->node.prev, struct urb_priv, node);
+		WARN_ON(list_empty(&purbp->td_list));
+		ptd = list_entry(purbp->td_list.prev, struct uhci_td,
+				list);
+		td = list_entry(urbp->td_list.prev, struct uhci_td,
+				list);
+		ptd->link = td->link;
+		goto done;
+	}
+
+	/* If the QH element pointer is UHCI_PTR_TERM then then currently
+	 * executing URB has already been unlinked, so this one isn't it. */
+	if (qh_element(qh) == UHCI_PTR_TERM(uhci))
+		goto done;
+	qh->element = UHCI_PTR_TERM(uhci);
+
+	/* Control pipes don't have to worry about toggles */
+	if (qh->type == USB_ENDPOINT_XFER_CONTROL)
+		goto done;
+
+	/* Save the next toggle value */
+	WARN_ON(list_empty(&urbp->td_list));
+	td = list_entry(urbp->td_list.next, struct uhci_td, list);
+	qh->needs_fixup = 1;
+	qh->initial_toggle = uhci_toggle(td_token(uhci, td));
+
+done:
+	return ret;
+}
+
+/*
+ * Fix up the data toggles for URBs in a queue, when one of them
+ * terminates early (short transfer, error, or dequeued).
+ */
+static void uhci_fixup_toggles(struct uhci_hcd *uhci, struct uhci_qh *qh,
+			int skip_first)
+{
+	struct urb_priv *urbp = NULL;
+	struct uhci_td *td;
+	unsigned int toggle = qh->initial_toggle;
+	unsigned int pipe;
+
+	/* Fixups for a short transfer start with the second URB in the
+	 * queue (the short URB is the first). */
+	if (skip_first)
+		urbp = list_entry(qh->queue.next, struct urb_priv, node);
+
+	/* When starting with the first URB, if the QH element pointer is
+	 * still valid then we know the URB's toggles are okay. */
+	else if (qh_element(qh) != UHCI_PTR_TERM(uhci))
+		toggle = 2;
+
+	/* Fix up the toggle for the URBs in the queue.  Normally this
+	 * loop won't run more than once: When an error or short transfer
+	 * occurs, the queue usually gets emptied. */
+	urbp = list_prepare_entry(urbp, &qh->queue, node);
+	list_for_each_entry_continue(urbp, &qh->queue, node) {
+
+		/* If the first TD has the right toggle value, we don't
+		 * need to change any toggles in this URB */
+		td = list_entry(urbp->td_list.next, struct uhci_td, list);
+		if (toggle > 1 || uhci_toggle(td_token(uhci, td)) == toggle) {
+			td = list_entry(urbp->td_list.prev, struct uhci_td,
+					list);
+			toggle = uhci_toggle(td_token(uhci, td)) ^ 1;
+
+		/* Otherwise all the toggles in the URB have to be switched */
+		} else {
+			list_for_each_entry(td, &urbp->td_list, list) {
+				td->token ^= cpu_to_hc32(uhci,
+							TD_TOKEN_TOGGLE);
+				toggle ^= 1;
+			}
+		}
+	}
+
+	wmb();
+	pipe = list_entry(qh->queue.next, struct urb_priv, node)->urb->pipe;
+	usb_settoggle(qh->udev, usb_pipeendpoint(pipe),
+			usb_pipeout(pipe), toggle);
+	qh->needs_fixup = 0;
+}
+
+/*
+ * Link an Isochronous QH into its skeleton's list
+ */
+static inline void link_iso(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	list_add_tail(&qh->node, &uhci->skel_iso_qh->node);
+
+	/* Isochronous QHs aren't linked by the hardware */
+}
+
+/*
+ * Link a high-period interrupt QH into the schedule at the end of its
+ * skeleton's list
+ */
+static void link_interrupt(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	struct uhci_qh *pqh;
+
+	list_add_tail(&qh->node, &uhci->skelqh[qh->skel]->node);
+
+	pqh = list_entry(qh->node.prev, struct uhci_qh, node);
+	qh->link = pqh->link;
+	wmb();
+	pqh->link = LINK_TO_QH(uhci, qh);
+}
+
+/*
+ * Link a period-1 interrupt or async QH into the schedule at the
+ * correct spot in the async skeleton's list, and update the FSBR link
+ */
+static void link_async(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	struct uhci_qh *pqh;
+	__hc32 link_to_new_qh;
+
+	/* Find the predecessor QH for our new one and insert it in the list.
+	 * The list of QHs is expected to be short, so linear search won't
+	 * take too long. */
+	list_for_each_entry_reverse(pqh, &uhci->skel_async_qh->node, node) {
+		if (pqh->skel <= qh->skel)
+			break;
+	}
+	list_add(&qh->node, &pqh->node);
+
+	/* Link it into the schedule */
+	qh->link = pqh->link;
+	wmb();
+	link_to_new_qh = LINK_TO_QH(uhci, qh);
+	pqh->link = link_to_new_qh;
+
+	/* If this is now the first FSBR QH, link the terminating skeleton
+	 * QH to it. */
+	if (pqh->skel < SKEL_FSBR && qh->skel >= SKEL_FSBR)
+		uhci->skel_term_qh->link = link_to_new_qh;
+}
+
+/*
+ * Put a QH on the schedule in both hardware and software
+ */
+static void uhci_activate_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	WARN_ON(list_empty(&qh->queue));
+
+	/* Set the element pointer if it isn't set already.
+	 * This isn't needed for Isochronous queues, but it doesn't hurt. */
+	if (qh_element(qh) == UHCI_PTR_TERM(uhci)) {
+		struct urb_priv *urbp = list_entry(qh->queue.next,
+				struct urb_priv, node);
+		struct uhci_td *td = list_entry(urbp->td_list.next,
+				struct uhci_td, list);
+
+		qh->element = LINK_TO_TD(uhci, td);
+	}
+
+	/* Treat the queue as if it has just advanced */
+	qh->wait_expired = 0;
+	qh->advance_jiffies = jiffies;
+
+	if (qh->state == QH_STATE_ACTIVE)
+		return;
+	qh->state = QH_STATE_ACTIVE;
+
+	/* Move the QH from its old list to the correct spot in the appropriate
+	 * skeleton's list */
+	if (qh == uhci->next_qh)
+		uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
+				node);
+	list_del(&qh->node);
+
+	if (qh->skel == SKEL_ISO)
+		link_iso(uhci, qh);
+	else if (qh->skel < SKEL_ASYNC)
+		link_interrupt(uhci, qh);
+	else
+		link_async(uhci, qh);
+}
+
+/*
+ * Unlink a high-period interrupt QH from the schedule
+ */
+static void unlink_interrupt(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	struct uhci_qh *pqh;
+
+	pqh = list_entry(qh->node.prev, struct uhci_qh, node);
+	pqh->link = qh->link;
+	mb();
+}
+
+/*
+ * Unlink a period-1 interrupt or async QH from the schedule
+ */
+static void unlink_async(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	struct uhci_qh *pqh;
+	__hc32 link_to_next_qh = qh->link;
+
+	pqh = list_entry(qh->node.prev, struct uhci_qh, node);
+	pqh->link = link_to_next_qh;
+
+	/* If this was the old first FSBR QH, link the terminating skeleton
+	 * QH to the next (new first FSBR) QH. */
+	if (pqh->skel < SKEL_FSBR && qh->skel >= SKEL_FSBR)
+		uhci->skel_term_qh->link = link_to_next_qh;
+	mb();
+}
+
+/*
+ * Take a QH off the hardware schedule
+ */
+static void uhci_unlink_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	if (qh->state == QH_STATE_UNLINKING)
+		return;
+	WARN_ON(qh->state != QH_STATE_ACTIVE || !qh->udev);
+	qh->state = QH_STATE_UNLINKING;
+
+	/* Unlink the QH from the schedule and record when we did it */
+	if (qh->skel == SKEL_ISO)
+		;
+	else if (qh->skel < SKEL_ASYNC)
+		unlink_interrupt(uhci, qh);
+	else
+		unlink_async(uhci, qh);
+
+	uhci_get_current_frame_number(uhci);
+	qh->unlink_frame = uhci->frame_number;
+
+	/* Force an interrupt so we know when the QH is fully unlinked */
+	if (list_empty(&uhci->skel_unlink_qh->node) || uhci->is_stopped)
+		uhci_set_next_interrupt(uhci);
+
+	/* Move the QH from its old list to the end of the unlinking list */
+	if (qh == uhci->next_qh)
+		uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
+				node);
+	list_move_tail(&qh->node, &uhci->skel_unlink_qh->node);
+}
+
+/*
+ * When we and the controller are through with a QH, it becomes IDLE.
+ * This happens when a QH has been off the schedule (on the unlinking
+ * list) for more than one frame, or when an error occurs while adding
+ * the first URB onto a new QH.
+ */
+static void uhci_make_qh_idle(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	WARN_ON(qh->state == QH_STATE_ACTIVE);
+
+	if (qh == uhci->next_qh)
+		uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
+				node);
+	list_move(&qh->node, &uhci->idle_qh_list);
+	qh->state = QH_STATE_IDLE;
+
+	/* Now that the QH is idle, its post_td isn't being used */
+	if (qh->post_td) {
+		uhci_free_td(uhci, qh->post_td);
+		qh->post_td = NULL;
+	}
+
+	/* If anyone is waiting for a QH to become idle, wake them up */
+	if (uhci->num_waiting)
+		wake_up_all(&uhci->waitqh);
+}
+
+/*
+ * Find the highest existing bandwidth load for a given phase and period.
+ */
+static int uhci_highest_load(struct uhci_hcd *uhci, int phase, int period)
+{
+	int highest_load = uhci->load[phase];
+
+	for (phase += period; phase < MAX_PHASE; phase += period)
+		highest_load = max_t(int, highest_load, uhci->load[phase]);
+	return highest_load;
+}
+
+/*
+ * Set qh->phase to the optimal phase for a periodic transfer and
+ * check whether the bandwidth requirement is acceptable.
+ */
+static int uhci_check_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	int minimax_load;
+
+	/* Find the optimal phase (unless it is already set) and get
+	 * its load value. */
+	if (qh->phase >= 0)
+		minimax_load = uhci_highest_load(uhci, qh->phase, qh->period);
+	else {
+		int phase, load;
+		int max_phase = min_t(int, MAX_PHASE, qh->period);
+
+		qh->phase = 0;
+		minimax_load = uhci_highest_load(uhci, qh->phase, qh->period);
+		for (phase = 1; phase < max_phase; ++phase) {
+			load = uhci_highest_load(uhci, phase, qh->period);
+			if (load < minimax_load) {
+				minimax_load = load;
+				qh->phase = phase;
+			}
+		}
+	}
+
+	/* Maximum allowable periodic bandwidth is 90%, or 900 us per frame */
+	if (minimax_load + qh->load > 900) {
+		dev_dbg(uhci_dev(uhci), "bandwidth allocation failed: "
+				"period %d, phase %d, %d + %d us\n",
+				qh->period, qh->phase, minimax_load, qh->load);
+		return -ENOSPC;
+	}
+	return 0;
+}
+
+/*
+ * Reserve a periodic QH's bandwidth in the schedule
+ */
+static void uhci_reserve_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	int i;
+	int load = qh->load;
+	char *p = "??";
+
+	for (i = qh->phase; i < MAX_PHASE; i += qh->period) {
+		uhci->load[i] += load;
+		uhci->total_load += load;
+	}
+	uhci_to_hcd(uhci)->self.bandwidth_allocated =
+			uhci->total_load / MAX_PHASE;
+	switch (qh->type) {
+	case USB_ENDPOINT_XFER_INT:
+		++uhci_to_hcd(uhci)->self.bandwidth_int_reqs;
+		p = "INT";
+		break;
+	case USB_ENDPOINT_XFER_ISOC:
+		++uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs;
+		p = "ISO";
+		break;
+	}
+	qh->bandwidth_reserved = 1;
+	dev_dbg(uhci_dev(uhci),
+			"%s dev %d ep%02x-%s, period %d, phase %d, %d us\n",
+			"reserve", qh->udev->devnum,
+			qh->hep->desc.bEndpointAddress, p,
+			qh->period, qh->phase, load);
+}
+
+/*
+ * Release a periodic QH's bandwidth reservation
+ */
+static void uhci_release_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	int i;
+	int load = qh->load;
+	char *p = "??";
+
+	for (i = qh->phase; i < MAX_PHASE; i += qh->period) {
+		uhci->load[i] -= load;
+		uhci->total_load -= load;
+	}
+	uhci_to_hcd(uhci)->self.bandwidth_allocated =
+			uhci->total_load / MAX_PHASE;
+	switch (qh->type) {
+	case USB_ENDPOINT_XFER_INT:
+		--uhci_to_hcd(uhci)->self.bandwidth_int_reqs;
+		p = "INT";
+		break;
+	case USB_ENDPOINT_XFER_ISOC:
+		--uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs;
+		p = "ISO";
+		break;
+	}
+	qh->bandwidth_reserved = 0;
+	dev_dbg(uhci_dev(uhci),
+			"%s dev %d ep%02x-%s, period %d, phase %d, %d us\n",
+			"release", qh->udev->devnum,
+			qh->hep->desc.bEndpointAddress, p,
+			qh->period, qh->phase, load);
+}
+
+static inline struct urb_priv *uhci_alloc_urb_priv(struct uhci_hcd *uhci,
+		struct urb *urb)
+{
+	struct urb_priv *urbp;
+
+	urbp = kmem_cache_zalloc(uhci_up_cachep, GFP_ATOMIC);
+	if (!urbp)
+		return NULL;
+
+	urbp->urb = urb;
+	urb->hcpriv = urbp;
+
+	INIT_LIST_HEAD(&urbp->node);
+	INIT_LIST_HEAD(&urbp->td_list);
+
+	return urbp;
+}
+
+static void uhci_free_urb_priv(struct uhci_hcd *uhci,
+		struct urb_priv *urbp)
+{
+	struct uhci_td *td, *tmp;
+
+	if (!list_empty(&urbp->node))
+		dev_WARN(uhci_dev(uhci), "urb %p still on QH's list!\n",
+				urbp->urb);
+
+	list_for_each_entry_safe(td, tmp, &urbp->td_list, list) {
+		uhci_remove_td_from_urbp(td);
+		uhci_free_td(uhci, td);
+	}
+
+	kmem_cache_free(uhci_up_cachep, urbp);
+}
+
+/*
+ * Map status to standard result codes
+ *
+ * <status> is (td_status(uhci, td) & 0xF60000), a.k.a.
+ * uhci_status_bits(td_status(uhci, td)).
+ * Note: <status> does not include the TD_CTRL_NAK bit.
+ * <dir_out> is True for output TDs and False for input TDs.
+ */
+static int uhci_map_status(int status, int dir_out)
+{
+	if (!status)
+		return 0;
+	if (status & TD_CTRL_BITSTUFF)			/* Bitstuff error */
+		return -EPROTO;
+	if (status & TD_CTRL_CRCTIMEO) {		/* CRC/Timeout */
+		if (dir_out)
+			return -EPROTO;
+		else
+			return -EILSEQ;
+	}
+	if (status & TD_CTRL_BABBLE)			/* Babble */
+		return -EOVERFLOW;
+	if (status & TD_CTRL_DBUFERR)			/* Buffer error */
+		return -ENOSR;
+	if (status & TD_CTRL_STALLED)			/* Stalled */
+		return -EPIPE;
+	return 0;
+}
+
+/*
+ * Control transfers
+ */
+static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
+		struct uhci_qh *qh)
+{
+	struct uhci_td *td;
+	unsigned long destination, status;
+	int maxsze = usb_endpoint_maxp(&qh->hep->desc);
+	int len = urb->transfer_buffer_length;
+	dma_addr_t data = urb->transfer_dma;
+	__hc32 *plink;
+	struct urb_priv *urbp = urb->hcpriv;
+	int skel;
+
+	/* The "pipe" thing contains the destination in bits 8--18 */
+	destination = (urb->pipe & PIPE_DEVEP_MASK) | USB_PID_SETUP;
+
+	/* 3 errors, dummy TD remains inactive */
+	status = uhci_maxerr(3);
+	if (urb->dev->speed == USB_SPEED_LOW)
+		status |= TD_CTRL_LS;
+
+	/*
+	 * Build the TD for the control request setup packet
+	 */
+	td = qh->dummy_td;
+	uhci_add_td_to_urbp(td, urbp);
+	uhci_fill_td(uhci, td, status, destination | uhci_explen(8),
+			urb->setup_dma);
+	plink = &td->link;
+	status |= TD_CTRL_ACTIVE;
+
+	/*
+	 * If direction is "send", change the packet ID from SETUP (0x2D)
+	 * to OUT (0xE1).  Else change it from SETUP to IN (0x69) and
+	 * set Short Packet Detect (SPD) for all data packets.
+	 *
+	 * 0-length transfers always get treated as "send".
+	 */
+	if (usb_pipeout(urb->pipe) || len == 0)
+		destination ^= (USB_PID_SETUP ^ USB_PID_OUT);
+	else {
+		destination ^= (USB_PID_SETUP ^ USB_PID_IN);
+		status |= TD_CTRL_SPD;
+	}
+
+	/*
+	 * Build the DATA TDs
+	 */
+	while (len > 0) {
+		int pktsze = maxsze;
+
+		if (len <= pktsze) {		/* The last data packet */
+			pktsze = len;
+			status &= ~TD_CTRL_SPD;
+		}
+
+		td = uhci_alloc_td(uhci);
+		if (!td)
+			goto nomem;
+		*plink = LINK_TO_TD(uhci, td);
+
+		/* Alternate Data0/1 (start with Data1) */
+		destination ^= TD_TOKEN_TOGGLE;
+
+		uhci_add_td_to_urbp(td, urbp);
+		uhci_fill_td(uhci, td, status,
+			destination | uhci_explen(pktsze), data);
+		plink = &td->link;
+
+		data += pktsze;
+		len -= pktsze;
+	}
+
+	/*
+	 * Build the final TD for control status
+	 */
+	td = uhci_alloc_td(uhci);
+	if (!td)
+		goto nomem;
+	*plink = LINK_TO_TD(uhci, td);
+
+	/* Change direction for the status transaction */
+	destination ^= (USB_PID_IN ^ USB_PID_OUT);
+	destination |= TD_TOKEN_TOGGLE;		/* End in Data1 */
+
+	uhci_add_td_to_urbp(td, urbp);
+	uhci_fill_td(uhci, td, status | TD_CTRL_IOC,
+			destination | uhci_explen(0), 0);
+	plink = &td->link;
+
+	/*
+	 * Build the new dummy TD and activate the old one
+	 */
+	td = uhci_alloc_td(uhci);
+	if (!td)
+		goto nomem;
+	*plink = LINK_TO_TD(uhci, td);
+
+	uhci_fill_td(uhci, td, 0, USB_PID_OUT | uhci_explen(0), 0);
+	wmb();
+	qh->dummy_td->status |= cpu_to_hc32(uhci, TD_CTRL_ACTIVE);
+	qh->dummy_td = td;
+
+	/* Low-speed transfers get a different queue, and won't hog the bus.
+	 * Also, some devices enumerate better without FSBR; the easiest way
+	 * to do that is to put URBs on the low-speed queue while the device
+	 * isn't in the CONFIGURED state. */
+	if (urb->dev->speed == USB_SPEED_LOW ||
+			urb->dev->state != USB_STATE_CONFIGURED)
+		skel = SKEL_LS_CONTROL;
+	else {
+		skel = SKEL_FS_CONTROL;
+		uhci_add_fsbr(uhci, urb);
+	}
+	if (qh->state != QH_STATE_ACTIVE)
+		qh->skel = skel;
+	return 0;
+
+nomem:
+	/* Remove the dummy TD from the td_list so it doesn't get freed */
+	uhci_remove_td_from_urbp(qh->dummy_td);
+	return -ENOMEM;
+}
+
+/*
+ * Common submit for bulk and interrupt
+ */
+static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb,
+		struct uhci_qh *qh)
+{
+	struct uhci_td *td;
+	unsigned long destination, status;
+	int maxsze = usb_endpoint_maxp(&qh->hep->desc);
+	int len = urb->transfer_buffer_length;
+	int this_sg_len;
+	dma_addr_t data;
+	__hc32 *plink;
+	struct urb_priv *urbp = urb->hcpriv;
+	unsigned int toggle;
+	struct scatterlist  *sg;
+	int i;
+
+	if (len < 0)
+		return -EINVAL;
+
+	/* The "pipe" thing contains the destination in bits 8--18 */
+	destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
+	toggle = usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
+			 usb_pipeout(urb->pipe));
+
+	/* 3 errors, dummy TD remains inactive */
+	status = uhci_maxerr(3);
+	if (urb->dev->speed == USB_SPEED_LOW)
+		status |= TD_CTRL_LS;
+	if (usb_pipein(urb->pipe))
+		status |= TD_CTRL_SPD;
+
+	i = urb->num_mapped_sgs;
+	if (len > 0 && i > 0) {
+		sg = urb->sg;
+		data = 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;
+		data = urb->transfer_dma;
+		this_sg_len = len;
+	}
+	/*
+	 * Build the DATA TDs
+	 */
+	plink = NULL;
+	td = qh->dummy_td;
+	for (;;) {	/* Allow zero length packets */
+		int pktsze = maxsze;
+
+		if (len <= pktsze) {		/* The last packet */
+			pktsze = len;
+			if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
+				status &= ~TD_CTRL_SPD;
+		}
+
+		if (plink) {
+			td = uhci_alloc_td(uhci);
+			if (!td)
+				goto nomem;
+			*plink = LINK_TO_TD(uhci, td);
+		}
+		uhci_add_td_to_urbp(td, urbp);
+		uhci_fill_td(uhci, td, status,
+				destination | uhci_explen(pktsze) |
+					(toggle << TD_TOKEN_TOGGLE_SHIFT),
+				data);
+		plink = &td->link;
+		status |= TD_CTRL_ACTIVE;
+
+		toggle ^= 1;
+		data += pktsze;
+		this_sg_len -= pktsze;
+		len -= maxsze;
+		if (this_sg_len <= 0) {
+			if (--i <= 0 || len <= 0)
+				break;
+			sg = sg_next(sg);
+			data = sg_dma_address(sg);
+			this_sg_len = min_t(int, sg_dma_len(sg), len);
+		}
+	}
+
+	/*
+	 * URB_ZERO_PACKET means adding a 0-length packet, if direction
+	 * is OUT and the transfer_length was an exact multiple of maxsze,
+	 * hence (len = transfer_length - N * maxsze) == 0
+	 * however, if transfer_length == 0, the zero packet was already
+	 * prepared above.
+	 */
+	if ((urb->transfer_flags & URB_ZERO_PACKET) &&
+			usb_pipeout(urb->pipe) && len == 0 &&
+			urb->transfer_buffer_length > 0) {
+		td = uhci_alloc_td(uhci);
+		if (!td)
+			goto nomem;
+		*plink = LINK_TO_TD(uhci, td);
+
+		uhci_add_td_to_urbp(td, urbp);
+		uhci_fill_td(uhci, td, status,
+				destination | uhci_explen(0) |
+					(toggle << TD_TOKEN_TOGGLE_SHIFT),
+				data);
+		plink = &td->link;
+
+		toggle ^= 1;
+	}
+
+	/* Set the interrupt-on-completion flag on the last packet.
+	 * A more-or-less typical 4 KB URB (= size of one memory page)
+	 * will require about 3 ms to transfer; that's a little on the
+	 * fast side but not enough to justify delaying an interrupt
+	 * more than 2 or 3 URBs, so we will ignore the URB_NO_INTERRUPT
+	 * flag setting. */
+	td->status |= cpu_to_hc32(uhci, TD_CTRL_IOC);
+
+	/*
+	 * Build the new dummy TD and activate the old one
+	 */
+	td = uhci_alloc_td(uhci);
+	if (!td)
+		goto nomem;
+	*plink = LINK_TO_TD(uhci, td);
+
+	uhci_fill_td(uhci, td, 0, USB_PID_OUT | uhci_explen(0), 0);
+	wmb();
+	qh->dummy_td->status |= cpu_to_hc32(uhci, TD_CTRL_ACTIVE);
+	qh->dummy_td = td;
+
+	usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
+			usb_pipeout(urb->pipe), toggle);
+	return 0;
+
+nomem:
+	/* Remove the dummy TD from the td_list so it doesn't get freed */
+	uhci_remove_td_from_urbp(qh->dummy_td);
+	return -ENOMEM;
+}
+
+static int uhci_submit_bulk(struct uhci_hcd *uhci, struct urb *urb,
+		struct uhci_qh *qh)
+{
+	int ret;
+
+	/* Can't have low-speed bulk transfers */
+	if (urb->dev->speed == USB_SPEED_LOW)
+		return -EINVAL;
+
+	if (qh->state != QH_STATE_ACTIVE)
+		qh->skel = SKEL_BULK;
+	ret = uhci_submit_common(uhci, urb, qh);
+	if (ret == 0)
+		uhci_add_fsbr(uhci, urb);
+	return ret;
+}
+
+static int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb,
+		struct uhci_qh *qh)
+{
+	int ret;
+
+	/* USB 1.1 interrupt transfers only involve one packet per interval.
+	 * Drivers can submit URBs of any length, but longer ones will need
+	 * multiple intervals to complete.
+	 */
+
+	if (!qh->bandwidth_reserved) {
+		int exponent;
+
+		/* Figure out which power-of-two queue to use */
+		for (exponent = 7; exponent >= 0; --exponent) {
+			if ((1 << exponent) <= urb->interval)
+				break;
+		}
+		if (exponent < 0)
+			return -EINVAL;
+
+		/* If the slot is full, try a lower period */
+		do {
+			qh->period = 1 << exponent;
+			qh->skel = SKEL_INDEX(exponent);
+
+			/* For now, interrupt phase is fixed by the layout
+			 * of the QH lists.
+			 */
+			qh->phase = (qh->period / 2) & (MAX_PHASE - 1);
+			ret = uhci_check_bandwidth(uhci, qh);
+		} while (ret != 0 && --exponent >= 0);
+		if (ret)
+			return ret;
+	} else if (qh->period > urb->interval)
+		return -EINVAL;		/* Can't decrease the period */
+
+	ret = uhci_submit_common(uhci, urb, qh);
+	if (ret == 0) {
+		urb->interval = qh->period;
+		if (!qh->bandwidth_reserved)
+			uhci_reserve_bandwidth(uhci, qh);
+	}
+	return ret;
+}
+
+/*
+ * Fix up the data structures following a short transfer
+ */
+static int uhci_fixup_short_transfer(struct uhci_hcd *uhci,
+		struct uhci_qh *qh, struct urb_priv *urbp)
+{
+	struct uhci_td *td;
+	struct list_head *tmp;
+	int ret;
+
+	td = list_entry(urbp->td_list.prev, struct uhci_td, list);
+	if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
+
+		/* When a control transfer is short, we have to restart
+		 * the queue at the status stage transaction, which is
+		 * the last TD. */
+		WARN_ON(list_empty(&urbp->td_list));
+		qh->element = LINK_TO_TD(uhci, td);
+		tmp = td->list.prev;
+		ret = -EINPROGRESS;
+
+	} else {
+
+		/* When a bulk/interrupt transfer is short, we have to
+		 * fix up the toggles of the following URBs on the queue
+		 * before restarting the queue at the next URB. */
+		qh->initial_toggle =
+			uhci_toggle(td_token(uhci, qh->post_td)) ^ 1;
+		uhci_fixup_toggles(uhci, qh, 1);
+
+		if (list_empty(&urbp->td_list))
+			td = qh->post_td;
+		qh->element = td->link;
+		tmp = urbp->td_list.prev;
+		ret = 0;
+	}
+
+	/* Remove all the TDs we skipped over, from tmp back to the start */
+	while (tmp != &urbp->td_list) {
+		td = list_entry(tmp, struct uhci_td, list);
+		tmp = tmp->prev;
+
+		uhci_remove_td_from_urbp(td);
+		uhci_free_td(uhci, td);
+	}
+	return ret;
+}
+
+/*
+ * Common result for control, bulk, and interrupt
+ */
+static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
+{
+	struct urb_priv *urbp = urb->hcpriv;
+	struct uhci_qh *qh = urbp->qh;
+	struct uhci_td *td, *tmp;
+	unsigned status;
+	int ret = 0;
+
+	list_for_each_entry_safe(td, tmp, &urbp->td_list, list) {
+		unsigned int ctrlstat;
+		int len;
+
+		ctrlstat = td_status(uhci, td);
+		status = uhci_status_bits(ctrlstat);
+		if (status & TD_CTRL_ACTIVE)
+			return -EINPROGRESS;
+
+		len = uhci_actual_length(ctrlstat);
+		urb->actual_length += len;
+
+		if (status) {
+			ret = uhci_map_status(status,
+					uhci_packetout(td_token(uhci, td)));
+			if ((debug == 1 && ret != -EPIPE) || debug > 1) {
+				/* Some debugging code */
+				dev_dbg(&urb->dev->dev,
+						"%s: failed with status %x\n",
+						__func__, status);
+
+				if (debug > 1 && errbuf) {
+					/* Print the chain for debugging */
+					uhci_show_qh(uhci, urbp->qh, errbuf,
+						ERRBUF_LEN - EXTRA_SPACE, 0);
+					lprintk(errbuf);
+				}
+			}
+
+		/* Did we receive a short packet? */
+		} else if (len < uhci_expected_length(td_token(uhci, td))) {
+
+			/* For control transfers, go to the status TD if
+			 * this isn't already the last data TD */
+			if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
+				if (td->list.next != urbp->td_list.prev)
+					ret = 1;
+			}
+
+			/* For bulk and interrupt, this may be an error */
+			else if (urb->transfer_flags & URB_SHORT_NOT_OK)
+				ret = -EREMOTEIO;
+
+			/* Fixup needed only if this isn't the URB's last TD */
+			else if (&td->list != urbp->td_list.prev)
+				ret = 1;
+		}
+
+		uhci_remove_td_from_urbp(td);
+		if (qh->post_td)
+			uhci_free_td(uhci, qh->post_td);
+		qh->post_td = td;
+
+		if (ret != 0)
+			goto err;
+	}
+	return ret;
+
+err:
+	if (ret < 0) {
+		/* Note that the queue has stopped and save
+		 * the next toggle value */
+		qh->element = UHCI_PTR_TERM(uhci);
+		qh->is_stopped = 1;
+		qh->needs_fixup = (qh->type != USB_ENDPOINT_XFER_CONTROL);
+		qh->initial_toggle = uhci_toggle(td_token(uhci, td)) ^
+				(ret == -EREMOTEIO);
+
+	} else		/* Short packet received */
+		ret = uhci_fixup_short_transfer(uhci, qh, urbp);
+	return ret;
+}
+
+/*
+ * Isochronous transfers
+ */
+static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb,
+		struct uhci_qh *qh)
+{
+	struct uhci_td *td = NULL;	/* Since urb->number_of_packets > 0 */
+	int i;
+	unsigned frame, next;
+	unsigned long destination, status;
+	struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
+
+	/* Values must not be too big (could overflow below) */
+	if (urb->interval >= UHCI_NUMFRAMES ||
+			urb->number_of_packets >= UHCI_NUMFRAMES)
+		return -EFBIG;
+
+	uhci_get_current_frame_number(uhci);
+
+	/* Check the period and figure out the starting frame number */
+	if (!qh->bandwidth_reserved) {
+		qh->period = urb->interval;
+		qh->phase = -1;		/* Find the best phase */
+		i = uhci_check_bandwidth(uhci, qh);
+		if (i)
+			return i;
+
+		/* Allow a little time to allocate the TDs */
+		next = uhci->frame_number + 10;
+		frame = qh->phase;
+
+		/* Round up to the first available slot */
+		frame += (next - frame + qh->period - 1) & -qh->period;
+
+	} else if (qh->period != urb->interval) {
+		return -EINVAL;		/* Can't change the period */
+
+	} else {
+		next = uhci->frame_number + 1;
+
+		/* Find the next unused frame */
+		if (list_empty(&qh->queue)) {
+			frame = qh->iso_frame;
+		} else {
+			struct urb *lurb;
+
+			lurb = list_entry(qh->queue.prev,
+					struct urb_priv, node)->urb;
+			frame = lurb->start_frame +
+					lurb->number_of_packets *
+					lurb->interval;
+		}
+
+		/* Fell behind? */
+		if (!uhci_frame_before_eq(next, frame)) {
+
+			/* USB_ISO_ASAP: Round up to the first available slot */
+			if (urb->transfer_flags & URB_ISO_ASAP)
+				frame += (next - frame + qh->period - 1) &
+						-qh->period;
+
+			/*
+			 * Not ASAP: Use the next slot in the stream,
+			 * no matter what.
+			 */
+			else if (!uhci_frame_before_eq(next,
+					frame + (urb->number_of_packets - 1) *
+						qh->period))
+				dev_dbg(uhci_dev(uhci), "iso underrun %p (%u+%u < %u)\n",
+						urb, frame,
+						(urb->number_of_packets - 1) *
+							qh->period,
+						next);
+		}
+	}
+
+	/* Make sure we won't have to go too far into the future */
+	if (uhci_frame_before_eq(uhci->last_iso_frame + UHCI_NUMFRAMES,
+			frame + urb->number_of_packets * urb->interval))
+		return -EFBIG;
+	urb->start_frame = frame;
+
+	status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
+	destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
+
+	for (i = 0; i < urb->number_of_packets; i++) {
+		td = uhci_alloc_td(uhci);
+		if (!td)
+			return -ENOMEM;
+
+		uhci_add_td_to_urbp(td, urbp);
+		uhci_fill_td(uhci, td, status, destination |
+				uhci_explen(urb->iso_frame_desc[i].length),
+				urb->transfer_dma +
+					urb->iso_frame_desc[i].offset);
+	}
+
+	/* Set the interrupt-on-completion flag on the last packet. */
+	td->status |= cpu_to_hc32(uhci, TD_CTRL_IOC);
+
+	/* Add the TDs to the frame list */
+	frame = urb->start_frame;
+	list_for_each_entry(td, &urbp->td_list, list) {
+		uhci_insert_td_in_frame_list(uhci, td, frame);
+		frame += qh->period;
+	}
+
+	if (list_empty(&qh->queue)) {
+		qh->iso_packet_desc = &urb->iso_frame_desc[0];
+		qh->iso_frame = urb->start_frame;
+	}
+
+	qh->skel = SKEL_ISO;
+	if (!qh->bandwidth_reserved)
+		uhci_reserve_bandwidth(uhci, qh);
+	return 0;
+}
+
+static int uhci_result_isochronous(struct uhci_hcd *uhci, struct urb *urb)
+{
+	struct uhci_td *td, *tmp;
+	struct urb_priv *urbp = urb->hcpriv;
+	struct uhci_qh *qh = urbp->qh;
+
+	list_for_each_entry_safe(td, tmp, &urbp->td_list, list) {
+		unsigned int ctrlstat;
+		int status;
+		int actlength;
+
+		if (uhci_frame_before_eq(uhci->cur_iso_frame, qh->iso_frame))
+			return -EINPROGRESS;
+
+		uhci_remove_tds_from_frame(uhci, qh->iso_frame);
+
+		ctrlstat = td_status(uhci, td);
+		if (ctrlstat & TD_CTRL_ACTIVE) {
+			status = -EXDEV;	/* TD was added too late? */
+		} else {
+			status = uhci_map_status(uhci_status_bits(ctrlstat),
+					usb_pipeout(urb->pipe));
+			actlength = uhci_actual_length(ctrlstat);
+
+			urb->actual_length += actlength;
+			qh->iso_packet_desc->actual_length = actlength;
+			qh->iso_packet_desc->status = status;
+		}
+		if (status)
+			urb->error_count++;
+
+		uhci_remove_td_from_urbp(td);
+		uhci_free_td(uhci, td);
+		qh->iso_frame += qh->period;
+		++qh->iso_packet_desc;
+	}
+	return 0;
+}
+
+static int uhci_urb_enqueue(struct usb_hcd *hcd,
+		struct urb *urb, gfp_t mem_flags)
+{
+	int ret;
+	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
+	unsigned long flags;
+	struct urb_priv *urbp;
+	struct uhci_qh *qh;
+
+	spin_lock_irqsave(&uhci->lock, flags);
+
+	ret = usb_hcd_link_urb_to_ep(hcd, urb);
+	if (ret)
+		goto done_not_linked;
+
+	ret = -ENOMEM;
+	urbp = uhci_alloc_urb_priv(uhci, urb);
+	if (!urbp)
+		goto done;
+
+	if (urb->ep->hcpriv)
+		qh = urb->ep->hcpriv;
+	else {
+		qh = uhci_alloc_qh(uhci, urb->dev, urb->ep);
+		if (!qh)
+			goto err_no_qh;
+	}
+	urbp->qh = qh;
+
+	switch (qh->type) {
+	case USB_ENDPOINT_XFER_CONTROL:
+		ret = uhci_submit_control(uhci, urb, qh);
+		break;
+	case USB_ENDPOINT_XFER_BULK:
+		ret = uhci_submit_bulk(uhci, urb, qh);
+		break;
+	case USB_ENDPOINT_XFER_INT:
+		ret = uhci_submit_interrupt(uhci, urb, qh);
+		break;
+	case USB_ENDPOINT_XFER_ISOC:
+		urb->error_count = 0;
+		ret = uhci_submit_isochronous(uhci, urb, qh);
+		break;
+	}
+	if (ret != 0)
+		goto err_submit_failed;
+
+	/* Add this URB to the QH */
+	list_add_tail(&urbp->node, &qh->queue);
+
+	/* If the new URB is the first and only one on this QH then either
+	 * the QH is new and idle or else it's unlinked and waiting to
+	 * become idle, so we can activate it right away.  But only if the
+	 * queue isn't stopped. */
+	if (qh->queue.next == &urbp->node && !qh->is_stopped) {
+		uhci_activate_qh(uhci, qh);
+		uhci_urbp_wants_fsbr(uhci, urbp);
+	}
+	goto done;
+
+err_submit_failed:
+	if (qh->state == QH_STATE_IDLE)
+		uhci_make_qh_idle(uhci, qh);	/* Reclaim unused QH */
+err_no_qh:
+	uhci_free_urb_priv(uhci, urbp);
+done:
+	if (ret)
+		usb_hcd_unlink_urb_from_ep(hcd, urb);
+done_not_linked:
+	spin_unlock_irqrestore(&uhci->lock, flags);
+	return ret;
+}
+
+static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
+{
+	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
+	unsigned long flags;
+	struct uhci_qh *qh;
+	int rc;
+
+	spin_lock_irqsave(&uhci->lock, flags);
+	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
+	if (rc)
+		goto done;
+
+	qh = ((struct urb_priv *) urb->hcpriv)->qh;
+
+	/* Remove Isochronous TDs from the frame list ASAP */
+	if (qh->type == USB_ENDPOINT_XFER_ISOC) {
+		uhci_unlink_isochronous_tds(uhci, urb);
+		mb();
+
+		/* If the URB has already started, update the QH unlink time */
+		uhci_get_current_frame_number(uhci);
+		if (uhci_frame_before_eq(urb->start_frame, uhci->frame_number))
+			qh->unlink_frame = uhci->frame_number;
+	}
+
+	uhci_unlink_qh(uhci, qh);
+
+done:
+	spin_unlock_irqrestore(&uhci->lock, flags);
+	return rc;
+}
+
+/*
+ * Finish unlinking an URB and give it back
+ */
+static void uhci_giveback_urb(struct uhci_hcd *uhci, struct uhci_qh *qh,
+		struct urb *urb, int status)
+__releases(uhci->lock)
+__acquires(uhci->lock)
+{
+	struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
+
+	if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
+
+		/* Subtract off the length of the SETUP packet from
+		 * urb->actual_length.
+		 */
+		urb->actual_length -= min_t(u32, 8, urb->actual_length);
+	}
+
+	/* When giving back the first URB in an Isochronous queue,
+	 * reinitialize the QH's iso-related members for the next URB. */
+	else if (qh->type == USB_ENDPOINT_XFER_ISOC &&
+			urbp->node.prev == &qh->queue &&
+			urbp->node.next != &qh->queue) {
+		struct urb *nurb = list_entry(urbp->node.next,
+				struct urb_priv, node)->urb;
+
+		qh->iso_packet_desc = &nurb->iso_frame_desc[0];
+		qh->iso_frame = nurb->start_frame;
+	}
+
+	/* Take the URB off the QH's queue.  If the queue is now empty,
+	 * this is a perfect time for a toggle fixup. */
+	list_del_init(&urbp->node);
+	if (list_empty(&qh->queue) && qh->needs_fixup) {
+		usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
+				usb_pipeout(urb->pipe), qh->initial_toggle);
+		qh->needs_fixup = 0;
+	}
+
+	uhci_free_urb_priv(uhci, urbp);
+	usb_hcd_unlink_urb_from_ep(uhci_to_hcd(uhci), urb);
+
+	spin_unlock(&uhci->lock);
+	usb_hcd_giveback_urb(uhci_to_hcd(uhci), urb, status);
+	spin_lock(&uhci->lock);
+
+	/* If the queue is now empty, we can unlink the QH and give up its
+	 * reserved bandwidth. */
+	if (list_empty(&qh->queue)) {
+		uhci_unlink_qh(uhci, qh);
+		if (qh->bandwidth_reserved)
+			uhci_release_bandwidth(uhci, qh);
+	}
+}
+
+/*
+ * Scan the URBs in a QH's queue
+ */
+#define QH_FINISHED_UNLINKING(qh)			\
+		(qh->state == QH_STATE_UNLINKING &&	\
+		uhci->frame_number + uhci->is_stopped != qh->unlink_frame)
+
+static void uhci_scan_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	struct urb_priv *urbp;
+	struct urb *urb;
+	int status;
+
+	while (!list_empty(&qh->queue)) {
+		urbp = list_entry(qh->queue.next, struct urb_priv, node);
+		urb = urbp->urb;
+
+		if (qh->type == USB_ENDPOINT_XFER_ISOC)
+			status = uhci_result_isochronous(uhci, urb);
+		else
+			status = uhci_result_common(uhci, urb);
+		if (status == -EINPROGRESS)
+			break;
+
+		/* Dequeued but completed URBs can't be given back unless
+		 * the QH is stopped or has finished unlinking. */
+		if (urb->unlinked) {
+			if (QH_FINISHED_UNLINKING(qh))
+				qh->is_stopped = 1;
+			else if (!qh->is_stopped)
+				return;
+		}
+
+		uhci_giveback_urb(uhci, qh, urb, status);
+		if (status < 0)
+			break;
+	}
+
+	/* If the QH is neither stopped nor finished unlinking (normal case),
+	 * our work here is done. */
+	if (QH_FINISHED_UNLINKING(qh))
+		qh->is_stopped = 1;
+	else if (!qh->is_stopped)
+		return;
+
+	/* Otherwise give back each of the dequeued URBs */
+restart:
+	list_for_each_entry(urbp, &qh->queue, node) {
+		urb = urbp->urb;
+		if (urb->unlinked) {
+
+			/* Fix up the TD links and save the toggles for
+			 * non-Isochronous queues.  For Isochronous queues,
+			 * test for too-recent dequeues. */
+			if (!uhci_cleanup_queue(uhci, qh, urb)) {
+				qh->is_stopped = 0;
+				return;
+			}
+			uhci_giveback_urb(uhci, qh, urb, 0);
+			goto restart;
+		}
+	}
+	qh->is_stopped = 0;
+
+	/* There are no more dequeued URBs.  If there are still URBs on the
+	 * queue, the QH can now be re-activated. */
+	if (!list_empty(&qh->queue)) {
+		if (qh->needs_fixup)
+			uhci_fixup_toggles(uhci, qh, 0);
+
+		/* If the first URB on the queue wants FSBR but its time
+		 * limit has expired, set the next TD to interrupt on
+		 * completion before reactivating the QH. */
+		urbp = list_entry(qh->queue.next, struct urb_priv, node);
+		if (urbp->fsbr && qh->wait_expired) {
+			struct uhci_td *td = list_entry(urbp->td_list.next,
+					struct uhci_td, list);
+
+			td->status |= cpu_to_hc32(uhci, TD_CTRL_IOC);
+		}
+
+		uhci_activate_qh(uhci, qh);
+	}
+
+	/* The queue is empty.  The QH can become idle if it is fully
+	 * unlinked. */
+	else if (QH_FINISHED_UNLINKING(qh))
+		uhci_make_qh_idle(uhci, qh);
+}
+
+/*
+ * Check for queues that have made some forward progress.
+ * Returns 0 if the queue is not Isochronous, is ACTIVE, and
+ * has not advanced since last examined; 1 otherwise.
+ *
+ * Early Intel controllers have a bug which causes qh->element sometimes
+ * not to advance when a TD completes successfully.  The queue remains
+ * stuck on the inactive completed TD.  We detect such cases and advance
+ * the element pointer by hand.
+ */
+static int uhci_advance_check(struct uhci_hcd *uhci, struct uhci_qh *qh)
+{
+	struct urb_priv *urbp = NULL;
+	struct uhci_td *td;
+	int ret = 1;
+	unsigned status;
+
+	if (qh->type == USB_ENDPOINT_XFER_ISOC)
+		goto done;
+
+	/* Treat an UNLINKING queue as though it hasn't advanced.
+	 * This is okay because reactivation will treat it as though
+	 * it has advanced, and if it is going to become IDLE then
+	 * this doesn't matter anyway.  Furthermore it's possible
+	 * for an UNLINKING queue not to have any URBs at all, or
+	 * for its first URB not to have any TDs (if it was dequeued
+	 * just as it completed).  So it's not easy in any case to
+	 * test whether such queues have advanced. */
+	if (qh->state != QH_STATE_ACTIVE) {
+		urbp = NULL;
+		status = 0;
+
+	} else {
+		urbp = list_entry(qh->queue.next, struct urb_priv, node);
+		td = list_entry(urbp->td_list.next, struct uhci_td, list);
+		status = td_status(uhci, td);
+		if (!(status & TD_CTRL_ACTIVE)) {
+
+			/* We're okay, the queue has advanced */
+			qh->wait_expired = 0;
+			qh->advance_jiffies = jiffies;
+			goto done;
+		}
+		ret = uhci->is_stopped;
+	}
+
+	/* The queue hasn't advanced; check for timeout */
+	if (qh->wait_expired)
+		goto done;
+
+	if (time_after(jiffies, qh->advance_jiffies + QH_WAIT_TIMEOUT)) {
+
+		/* Detect the Intel bug and work around it */
+		if (qh->post_td && qh_element(qh) ==
+			LINK_TO_TD(uhci, qh->post_td)) {
+			qh->element = qh->post_td->link;
+			qh->advance_jiffies = jiffies;
+			ret = 1;
+			goto done;
+		}
+
+		qh->wait_expired = 1;
+
+		/* If the current URB wants FSBR, unlink it temporarily
+		 * so that we can safely set the next TD to interrupt on
+		 * completion.  That way we'll know as soon as the queue
+		 * starts moving again. */
+		if (urbp && urbp->fsbr && !(status & TD_CTRL_IOC))
+			uhci_unlink_qh(uhci, qh);
+
+	} else {
+		/* Unmoving but not-yet-expired queues keep FSBR alive */
+		if (urbp)
+			uhci_urbp_wants_fsbr(uhci, urbp);
+	}
+
+done:
+	return ret;
+}
+
+/*
+ * Process events in the schedule, but only in one thread at a time
+ */
+static void uhci_scan_schedule(struct uhci_hcd *uhci)
+{
+	int i;
+	struct uhci_qh *qh;
+
+	/* Don't allow re-entrant calls */
+	if (uhci->scan_in_progress) {
+		uhci->need_rescan = 1;
+		return;
+	}
+	uhci->scan_in_progress = 1;
+rescan:
+	uhci->need_rescan = 0;
+	uhci->fsbr_is_wanted = 0;
+
+	uhci_clear_next_interrupt(uhci);
+	uhci_get_current_frame_number(uhci);
+	uhci->cur_iso_frame = uhci->frame_number;
+
+	/* Go through all the QH queues and process the URBs in each one */
+	for (i = 0; i < UHCI_NUM_SKELQH - 1; ++i) {
+		uhci->next_qh = list_entry(uhci->skelqh[i]->node.next,
+				struct uhci_qh, node);
+		while ((qh = uhci->next_qh) != uhci->skelqh[i]) {
+			uhci->next_qh = list_entry(qh->node.next,
+					struct uhci_qh, node);
+
+			if (uhci_advance_check(uhci, qh)) {
+				uhci_scan_qh(uhci, qh);
+				if (qh->state == QH_STATE_ACTIVE) {
+					uhci_urbp_wants_fsbr(uhci,
+	list_entry(qh->queue.next, struct urb_priv, node));
+				}
+			}
+		}
+	}
+
+	uhci->last_iso_frame = uhci->cur_iso_frame;
+	if (uhci->need_rescan)
+		goto rescan;
+	uhci->scan_in_progress = 0;
+
+	if (uhci->fsbr_is_on && !uhci->fsbr_is_wanted &&
+			!uhci->fsbr_expiring) {
+		uhci->fsbr_expiring = 1;
+		mod_timer(&uhci->fsbr_timer, jiffies + FSBR_OFF_DELAY);
+	}
+
+	if (list_empty(&uhci->skel_unlink_qh->node))
+		uhci_clear_next_interrupt(uhci);
+	else
+		uhci_set_next_interrupt(uhci);
+}