[PATCH] UHCI: use one QH per endpoint, not per URB

This patch (as623) changes the uhci-hcd driver to make it use one QH per
device endpoint, instead of a QH per URB as it does now.  Numerous areas
of the code are affected by this.  For example, the distinction between
"queued" URBs and non-"queued" URBs no longer exists; all URBs belong to
a queue and some just happen to be at the queue's head.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 456 insertions, 529 deletions

diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c
index 782398045f9f..b1b551a3d14e 100644
--- a/drivers/usb/host/uhci-q.c
+++ b/drivers/usb/host/uhci-q.c
@@ -13,13 +13,9 @@
  * (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 Alan Stern, stern@rowland.harvard.edu
+ * (C) Copyright 2004-2005 Alan Stern, stern@rowland.harvard.edu
  */
 
-static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb);
-static void uhci_unlink_generic(struct uhci_hcd *uhci, struct urb *urb);
-static void uhci_remove_pending_urbps(struct uhci_hcd *uhci);
-static void uhci_free_pending_qhs(struct uhci_hcd *uhci);
 static void uhci_free_pending_tds(struct uhci_hcd *uhci);
 
 /*
@@ -30,7 +26,7 @@ static void uhci_free_pending_tds(struct uhci_hcd *uhci);
  * 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 inline void uhci_set_next_interrupt(struct uhci_hcd *uhci)
+static void uhci_set_next_interrupt(struct uhci_hcd *uhci)
 {
         if (uhci->is_stopped)
                 mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
@@ -42,12 +38,6 @@ static inline void uhci_clear_next_interrupt(struct uhci_hcd *uhci)
         uhci->term_td->status &= ~cpu_to_le32(TD_CTRL_IOC);
 }
 
-static inline void uhci_moveto_complete(struct uhci_hcd *uhci, 
-                                        struct urb_priv *urbp)
-{
-        list_move_tail(&urbp->urb_list, &uhci->complete_list);
-}
-
 static struct uhci_td *uhci_alloc_td(struct uhci_hcd *uhci)
 {
         dma_addr_t dma_handle;
@@ -71,6 +61,18 @@ static struct uhci_td *uhci_alloc_td(struct uhci_hcd *uhci)
         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->remove_list))
+                dev_warn(uhci_dev(uhci), "td %p still in remove_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_td *td, u32 status,
                 u32 token, u32 buffer)
 {
@@ -82,7 +84,8 @@ static inline void uhci_fill_td(struct uhci_td *td, u32 status,
 /*
  * We insert Isochronous URBs directly into the frame list at the beginning
  */
-static void uhci_insert_td_frame_list(struct uhci_hcd *uhci, struct uhci_td *td, unsigned framenum)
+static inline void uhci_insert_td_in_frame_list(struct uhci_hcd *uhci,
+                struct uhci_td *td, unsigned framenum)
 {
         framenum &= (UHCI_NUMFRAMES - 1);
 
@@ -108,7 +111,7 @@ static void uhci_insert_td_frame_list(struct uhci_hcd *uhci, struct uhci_td *td,
         }
 }
 
-static inline void uhci_remove_td_frame_list(struct uhci_hcd *uhci,
+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 */
@@ -139,48 +142,68 @@ static inline void uhci_remove_td_frame_list(struct uhci_hcd *uhci,
         td->frame = -1;
 }
 
-static void unlink_isochronous_tds(struct uhci_hcd *uhci, struct urb *urb)
+/*
+ * 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_frame_list(uhci, td);
+                uhci_remove_td_from_frame_list(uhci, td);
         wmb();
 }
 
 /*
- * Inserts a td list into qh.
+ * Remove an URB's TDs from the hardware schedule
  */
-static void uhci_insert_tds_in_qh(struct uhci_qh *qh, struct urb *urb, __le32 breadth)
+static void uhci_remove_tds_from_schedule(struct uhci_hcd *uhci,
+                struct urb *urb, int status)
 {
-        struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
-        struct uhci_td *td;
-        __le32 *plink;
+        struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 
-        /* Ordering isn't important here yet since the QH hasn't been */
-        /* inserted into the schedule yet */
-        plink = &qh->element;
-        list_for_each_entry(td, &urbp->td_list, list) {
-                *plink = cpu_to_le32(td->dma_handle) | breadth;
-                plink = &td->link;
+        /* Isochronous TDs get unlinked directly from the frame list */
+        if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
+                uhci_unlink_isochronous_tds(uhci, urb);
+                return;
         }
-        *plink = UHCI_PTR_TERM;
-}
 
-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->remove_list))
-                dev_warn(uhci_dev(uhci), "td %p still in remove_list!\n", td);
-        if (!list_empty(&td->fl_list))
-                dev_warn(uhci_dev(uhci), "td %p still in fl_list!\n", td);
+        /* If the URB isn't first on its queue, adjust the link pointer
+         * of the last TD in the previous URB. */
+        if (urbp->node.prev != &urbp->qh->queue) {
+                struct urb_priv *purbp;
+                struct uhci_td *ptd, *ltd;
+
+                if (status == -EINPROGRESS)
+                        status = 0;
+                purbp = list_entry(urbp->node.prev, struct urb_priv, node);
+                ptd = list_entry(purbp->td_list.prev, struct uhci_td,
+                                list);
+                ltd = list_entry(urbp->td_list.prev, struct uhci_td,
+                                list);
+                ptd->link = ltd->link;
+        }
 
-        dma_pool_free(uhci->td_pool, td, td->dma_handle);
+        /* If the URB completed with an error, then the QH element certainly
+         * points to one of the URB's TDs.  If it completed normally then
+         * the QH element has certainly moved on to the next URB.  And if
+         * the URB is still in progress then it must have been dequeued.
+         * The QH element either hasn't reached it yet or is somewhere in
+         * the middle.  If the URB wasn't first we can assume that it
+         * hasn't started yet (see above): Otherwise all the preceding URBs
+         * would have completed and been removed from the queue, so this one
+         * _would_ be first.
+         *
+         * If the QH element is inside this URB, clear it.  It will be
+         * set properly when the QH is activated.
+         */
+        if (status < 0)
+                urbp->qh->element = UHCI_PTR_TERM;
 }
 
-static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci)
+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;
@@ -194,256 +217,120 @@ static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci)
         qh->element = UHCI_PTR_TERM;
         qh->link = UHCI_PTR_TERM;
 
-        qh->urbp = NULL;
+        INIT_LIST_HEAD(&qh->queue);
+        INIT_LIST_HEAD(&qh->node);
 
-        INIT_LIST_HEAD(&qh->list);
-        INIT_LIST_HEAD(&qh->remove_list);
+        if (udev) {             /* Normal QH */
+                qh->state = QH_STATE_IDLE;
+                qh->hep = hep;
+                qh->udev = udev;
+                hep->hcpriv = qh;
+                usb_get_dev(udev);
 
+        } else {                /* Skeleton QH */
+                qh->state = QH_STATE_ACTIVE;
+                qh->udev = NULL;
+        }
         return qh;
 }
 
 static void uhci_free_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 {
-        if (!list_empty(&qh->list))
+        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);
-        if (!list_empty(&qh->remove_list))
-                dev_warn(uhci_dev(uhci), "qh %p still in remove_list!\n", qh);
 
+        list_del(&qh->node);
+        if (qh->udev) {
+                qh->hep->hcpriv = NULL;
+                usb_put_dev(qh->udev);
+        }
         dma_pool_free(uhci->qh_pool, qh, qh->dma_handle);
 }
 
 /*
- * Append this urb's qh after the last qh in skelqh->list
- *
- * Note that urb_priv.queue_list doesn't have a separate queue head;
- * it's a ring with every element "live".
+ * Put a QH on the schedule in both hardware and software
  */
-static void uhci_insert_qh(struct uhci_hcd *uhci, struct uhci_qh *skelqh, struct urb *urb)
+static void uhci_activate_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 {
-        struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
-        struct urb_priv *turbp;
-        struct uhci_qh *lqh;
+        struct uhci_qh *pqh;
 
-        /* Grab the last QH */
-        lqh = list_entry(skelqh->list.prev, struct uhci_qh, list);
+        WARN_ON(list_empty(&qh->queue));
 
-        /* Point to the next skelqh */
-        urbp->qh->link = lqh->link;
-        wmb();                          /* Ordering is important */
+        /* 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) {
+                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);
 
-        /*
-         * Patch QHs for previous endpoint's queued URBs?  HC goes
-         * here next, not to the next skelqh it now points to.
-         *
-         *    lqh --> td ... --> qh ... --> td --> qh ... --> td
-         *     |                 |                 |
-         *     v                 v                 v
-         *     +<----------------+-----------------+
-         *     v
-         *    newqh --> td ... --> td
-         *     |
-         *     v
-         *    ...
-         *
-         * The HC could see (and use!) any of these as we write them.
-         */
-        lqh->link = cpu_to_le32(urbp->qh->dma_handle) | UHCI_PTR_QH;
-        if (lqh->urbp) {
-                list_for_each_entry(turbp, &lqh->urbp->queue_list, queue_list)
-                        turbp->qh->link = lqh->link;
+                qh->element = cpu_to_le32(td->dma_handle);
         }
 
-        list_add_tail(&urbp->qh->list, &skelqh->list);
+        if (qh->state == QH_STATE_ACTIVE)
+                return;
+        qh->state = QH_STATE_ACTIVE;
+
+        /* Move the QH from its old list to the end of the appropriate
+         * skeleton's list */
+        list_move_tail(&qh->node, &qh->skel->node);
+
+        /* Link it into the schedule */
+        pqh = list_entry(qh->node.prev, struct uhci_qh, node);
+        qh->link = pqh->link;
+        wmb();
+        pqh->link = UHCI_PTR_QH | cpu_to_le32(qh->dma_handle);
 }
 
 /*
- * Start removal of QH from schedule; it finishes next frame.
- * TDs should be unlinked before this is called.
+ * Take a QH off the hardware schedule
  */
-static void uhci_remove_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
+static void uhci_unlink_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 {
         struct uhci_qh *pqh;
-        __le32 newlink;
 
-        if (!qh)
+        if (qh->state == QH_STATE_UNLINKING)
                 return;
+        WARN_ON(qh->state != QH_STATE_ACTIVE || !qh->udev);
+        qh->state = QH_STATE_UNLINKING;
 
-        /*
-         * Only go through the hoops if it's actually linked in
-         */
-        if (!list_empty(&qh->list)) {
-
-                /* If our queue is nonempty, make the next URB the head */
-                if (!list_empty(&qh->urbp->queue_list)) {
-                        struct urb_priv *nurbp;
-
-                        nurbp = list_entry(qh->urbp->queue_list.next,
-                                        struct urb_priv, queue_list);
-                        nurbp->queued = 0;
-                        list_add(&nurbp->qh->list, &qh->list);
-                        newlink = cpu_to_le32(nurbp->qh->dma_handle) | UHCI_PTR_QH;
-                } else
-                        newlink = qh->link;
-
-                /* Fix up the previous QH's queue to link to either
-                 * the new head of this queue or the start of the
-                 * next endpoint's queue. */
-                pqh = list_entry(qh->list.prev, struct uhci_qh, list);
-                pqh->link = newlink;
-                if (pqh->urbp) {
-                        struct urb_priv *turbp;
-
-                        list_for_each_entry(turbp, &pqh->urbp->queue_list,
-                                        queue_list)
-                                turbp->qh->link = newlink;
-                }
-                wmb();
-
-                /* Leave qh->link in case the HC is on the QH now, it will */
-                /* continue the rest of the schedule */
-                qh->element = UHCI_PTR_TERM;
-
-                list_del_init(&qh->list);
-        }
-
-        list_del_init(&qh->urbp->queue_list);
-        qh->urbp = NULL;
+        /* Unlink the QH from the schedule and record when we did it */
+        pqh = list_entry(qh->node.prev, struct uhci_qh, node);
+        pqh->link = qh->link;
+        mb();
 
         uhci_get_current_frame_number(uhci);
-        if (uhci->frame_number + uhci->is_stopped != uhci->qh_remove_age) {
-                uhci_free_pending_qhs(uhci);
-                uhci->qh_remove_age = uhci->frame_number;
-        }
+        qh->unlink_frame = uhci->frame_number;
 
-        /* Check to see if the remove list is empty. Set the IOC bit */
-        /* to force an interrupt so we can remove the QH */
-        if (list_empty(&uhci->qh_remove_list))
+        /* Force an interrupt so we know when the QH is fully unlinked */
+        if (list_empty(&uhci->skel_unlink_qh->node))
                 uhci_set_next_interrupt(uhci);
 
-        list_add(&qh->remove_list, &uhci->qh_remove_list);
+        /* Move the QH from its old list to the end of the unlinking list */
+        list_move_tail(&qh->node, &uhci->skel_unlink_qh->node);
 }
 
-static int uhci_fixup_toggle(struct urb *urb, unsigned int toggle)
-{
-        struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
-        struct uhci_td *td;
-
-        list_for_each_entry(td, &urbp->td_list, list) {
-                if (toggle)
-                        td->token |= cpu_to_le32(TD_TOKEN_TOGGLE);
-                else
-                        td->token &= ~cpu_to_le32(TD_TOKEN_TOGGLE);
-
-                toggle ^= 1;
-        }
-
-        return toggle;
-}
-
-/* This function will append one URB's QH to another URB's QH. This is for */
-/* queuing interrupt, control or bulk transfers */
-static void uhci_append_queued_urb(struct uhci_hcd *uhci, struct urb *eurb, struct urb *urb)
-{
-        struct urb_priv *eurbp, *urbp, *furbp, *lurbp;
-        struct uhci_td *lltd;
-
-        eurbp = eurb->hcpriv;
-        urbp = urb->hcpriv;
-
-        /* Find the first URB in the queue */
-        furbp = eurbp;
-        if (eurbp->queued) {
-                list_for_each_entry(furbp, &eurbp->queue_list, queue_list)
-                        if (!furbp->queued)
-                                break;
-        }
-
-        lurbp = list_entry(furbp->queue_list.prev, struct urb_priv, queue_list);
-
-        lltd = list_entry(lurbp->td_list.prev, struct uhci_td, list);
-
-        /* Control transfers always start with toggle 0 */
-        if (!usb_pipecontrol(urb->pipe))
-                usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
-                                usb_pipeout(urb->pipe),
-                                uhci_fixup_toggle(urb,
-                                        uhci_toggle(td_token(lltd)) ^ 1));
-
-        /* All qhs in the queue need to link to the next queue */
-        urbp->qh->link = eurbp->qh->link;
-
-        wmb();                  /* Make sure we flush everything */
-
-        lltd->link = cpu_to_le32(urbp->qh->dma_handle) | UHCI_PTR_QH;
-
-        list_add_tail(&urbp->queue_list, &furbp->queue_list);
-
-        urbp->queued = 1;
-}
-
-static void uhci_delete_queued_urb(struct uhci_hcd *uhci, struct urb *urb)
+/*
+ * 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)
 {
-        struct urb_priv *urbp, *nurbp, *purbp, *turbp;
-        struct uhci_td *pltd;
-        unsigned int toggle;
-
-        urbp = urb->hcpriv;
-
-        if (list_empty(&urbp->queue_list))
-                return;
-
-        nurbp = list_entry(urbp->queue_list.next, struct urb_priv, queue_list);
-
-        /*
-         * Fix up the toggle for the following URBs in the queue.
-         * Only needed for bulk and interrupt: control and isochronous
-         * endpoints don't propagate toggles between messages.
-         */
-        if (usb_pipebulk(urb->pipe) || usb_pipeint(urb->pipe)) {
-                if (!urbp->queued)
-                        /* We just set the toggle in uhci_unlink_generic */
-                        toggle = usb_gettoggle(urb->dev,
-                                        usb_pipeendpoint(urb->pipe),
-                                        usb_pipeout(urb->pipe));
-                else {
-                        /* If we're in the middle of the queue, grab the */
-                        /* toggle from the TD previous to us */
-                        purbp = list_entry(urbp->queue_list.prev,
-                                        struct urb_priv, queue_list);
-                        pltd = list_entry(purbp->td_list.prev,
-                                        struct uhci_td, list);
-                        toggle = uhci_toggle(td_token(pltd)) ^ 1;
-                }
-
-                list_for_each_entry(turbp, &urbp->queue_list, queue_list) {
-                        if (!turbp->queued)
-                                break;
-                        toggle = uhci_fixup_toggle(turbp->urb, toggle);
-                }
+        WARN_ON(qh->state == QH_STATE_ACTIVE);
 
-                usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
-                                usb_pipeout(urb->pipe), toggle);
-        }
-
-        if (urbp->queued) {
-                /* We're somewhere in the middle (or end).  The case where
-                 * we're at the head is handled in uhci_remove_qh(). */
-                purbp = list_entry(urbp->queue_list.prev, struct urb_priv,
-                                queue_list);
-
-                pltd = list_entry(purbp->td_list.prev, struct uhci_td, list);
-                if (nurbp->queued)
-                        pltd->link = cpu_to_le32(nurbp->qh->dma_handle) | UHCI_PTR_QH;
-                else
-                        /* The next URB happens to be the beginning, so */
-                        /*  we're the last, end the chain */
-                        pltd->link = UHCI_PTR_TERM;
-        }
+        list_move(&qh->node, &uhci->idle_qh_list);
+        qh->state = QH_STATE_IDLE;
 
-        /* urbp->queue_list is handled in uhci_remove_qh() */
+        /* If anyone is waiting for a QH to become idle, wake them up */
+        if (uhci->num_waiting)
+                wake_up_all(&uhci->waitqh);
 }
 
-static struct urb_priv *uhci_alloc_urb_priv(struct uhci_hcd *uhci, struct urb *urb)
+static inline struct urb_priv *uhci_alloc_urb_priv(struct uhci_hcd *uhci,
+                struct urb *urb)
 {
         struct urb_priv *urbp;
 
@@ -453,17 +340,14 @@ static struct urb_priv *uhci_alloc_urb_priv(struct uhci_hcd *uhci, struct urb *u
 
         memset((void *)urbp, 0, sizeof(*urbp));
 
-        urbp->fsbrtime = jiffies;
         urbp->urb = urb;
+        urb->hcpriv = urbp;
+        urbp->fsbrtime = jiffies;
         
+        INIT_LIST_HEAD(&urbp->node);
         INIT_LIST_HEAD(&urbp->td_list);
-        INIT_LIST_HEAD(&urbp->queue_list);
         INIT_LIST_HEAD(&urbp->urb_list);
 
-        list_add_tail(&urbp->urb_list, &uhci->urb_list);
-
-        urb->hcpriv = urbp;
-
         return urbp;
 }
 
@@ -482,18 +366,17 @@ static void uhci_remove_td_from_urb(struct uhci_td *td)
         list_del_init(&td->list);
 }
 
-static void uhci_destroy_urb_priv(struct uhci_hcd *uhci, struct urb *urb)
+static void uhci_free_urb_priv(struct uhci_hcd *uhci,
+                struct urb_priv *urbp)
 {
         struct uhci_td *td, *tmp;
-        struct urb_priv *urbp;
-
-        urbp = (struct urb_priv *)urb->hcpriv;
-        if (!urbp)
-                return;
 
         if (!list_empty(&urbp->urb_list))
-                dev_warn(uhci_dev(uhci), "urb %p still on uhci->urb_list "
-                                "or uhci->remove_list!\n", urb);
+                dev_warn(uhci_dev(uhci), "urb %p still on uhci->urb_list!\n",
+                                urbp->urb);
+        if (!list_empty(&urbp->node))
+                dev_warn(uhci_dev(uhci), "urb %p still on QH's list!\n",
+                                urbp->urb);
 
         uhci_get_current_frame_number(uhci);
         if (uhci->frame_number + uhci->is_stopped != uhci->td_remove_age) {
@@ -502,7 +385,7 @@ static void uhci_destroy_urb_priv(struct uhci_hcd *uhci, struct urb *urb)
         }
 
         /* Check to see if the remove list is empty. Set the IOC bit */
-        /* to force an interrupt so we can remove the TDs*/
+        /* to force an interrupt so we can remove the TDs. */
         if (list_empty(&uhci->td_remove_list))
                 uhci_set_next_interrupt(uhci);
 
@@ -511,7 +394,7 @@ static void uhci_destroy_urb_priv(struct uhci_hcd *uhci, struct urb *urb)
                 list_add(&td->remove_list, &uhci->td_remove_list);
         }
 
-        urb->hcpriv = NULL;
+        urbp->urb->hcpriv = NULL;
         kmem_cache_free(uhci_up_cachep, urbp);
 }
 
@@ -568,17 +451,82 @@ static int uhci_map_status(int status, int dir_out)
 }
 
 /*
+ * 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 urb *urb)
+{
+        struct list_head *head;
+        struct uhci_td *td;
+        struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
+        int prevactive = 0;
+        unsigned int toggle = 0;
+        struct urb_priv *turbp, *list_end;
+
+        /*
+         * We need to find out what the last successful toggle was so
+         * we can update the data toggles for the following transfers.
+         *
+         * There are 2 ways the last successful completed TD is found:
+         *
+         * 1) The TD is NOT active and the actual length < expected length
+         * 2) The TD is NOT active and it's the last TD in the chain
+         *
+         * and a third way the first uncompleted TD is found:
+         *
+         * 3) The TD is active and the previous TD is NOT active
+         */
+        head = &urbp->td_list;
+        list_for_each_entry(td, head, list) {
+                unsigned int ctrlstat = td_status(td);
+
+                if (!(ctrlstat & TD_CTRL_ACTIVE) &&
+                                (uhci_actual_length(ctrlstat) <
+                                 uhci_expected_length(td_token(td)) ||
+                                td->list.next == head))
+                        toggle = uhci_toggle(td_token(td)) ^ 1;
+                else if ((ctrlstat & TD_CTRL_ACTIVE) && !prevactive)
+                        toggle = uhci_toggle(td_token(td));
+
+                prevactive = ctrlstat & TD_CTRL_ACTIVE;
+        }
+
+        /*
+         * Fix up the toggle for the following URBs in the queue.
+         *
+         * We can stop as soon as we find an URB with toggles set correctly,
+         * because then all the following URBs will be correct also.
+         */
+        list_end = list_entry(&urbp->qh->queue, struct urb_priv, node);
+        turbp = urbp;
+        while ((turbp = list_entry(turbp->node.next, struct urb_priv, node))
+                        != list_end) {
+                td = list_entry(turbp->td_list.next, struct uhci_td, list);
+                if (uhci_toggle(td_token(td)) == toggle)
+                        return;
+
+                list_for_each_entry(td, &turbp->td_list, list) {
+                        td->token ^= __constant_cpu_to_le32(TD_TOKEN_TOGGLE);
+                        toggle ^= 1;
+                }
+        }
+
+        usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
+                        usb_pipeout(urb->pipe), toggle);
+}
+
+/*
  * Control transfers
  */
-static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb, struct urb *eurb)
+static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
+                struct uhci_qh *qh)
 {
-        struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
         struct uhci_td *td;
-        struct uhci_qh *qh, *skelqh;
         unsigned long destination, status;
-        int maxsze = usb_maxpacket(urb->dev, urb->pipe, usb_pipeout(urb->pipe));
+        int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize);
         int len = urb->transfer_buffer_length;
         dma_addr_t data = urb->transfer_dma;
+        __le32 *plink;
 
         /* The "pipe" thing contains the destination in bits 8--18 */
         destination = (urb->pipe & PIPE_DEVEP_MASK) | USB_PID_SETUP;
@@ -597,7 +545,8 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb, struct ur
 
         uhci_add_td_to_urb(urb, td);
         uhci_fill_td(td, status, destination | uhci_explen(8),
-                urb->setup_dma);
+                        urb->setup_dma);
+        plink = &td->link;
 
         /*
          * If direction is "send", change the packet ID from SETUP (0x2D)
@@ -615,21 +564,20 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb, struct ur
          * Build the DATA TDs
          */
         while (len > 0) {
-                int pktsze = len;
-
-                if (pktsze > maxsze)
-                        pktsze = maxsze;
+                int pktsze = min(len, maxsze);
 
                 td = uhci_alloc_td(uhci);
                 if (!td)
                         return -ENOMEM;
+                *plink = cpu_to_le32(td->dma_handle);
 
                 /* Alternate Data0/1 (start with Data1) */
                 destination ^= TD_TOKEN_TOGGLE;
         
                 uhci_add_td_to_urb(urb, td);
                 uhci_fill_td(td, status, destination | uhci_explen(pktsze),
-                        data);
+                                data);
+                plink = &td->link;
 
                 data += pktsze;
                 len -= pktsze;
@@ -641,6 +589,7 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb, struct ur
         td = uhci_alloc_td(uhci);
         if (!td)
                 return -ENOMEM;
+        *plink = cpu_to_le32(td->dma_handle);
 
         /*
          * It's IN if the pipe is an output pipe or we're not expecting
@@ -658,16 +607,7 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb, struct ur
 
         uhci_add_td_to_urb(urb, td);
         uhci_fill_td(td, status | TD_CTRL_IOC,
-                destination | uhci_explen(0), 0);
-
-        qh = uhci_alloc_qh(uhci);
-        if (!qh)
-                return -ENOMEM;
-
-        urbp->qh = qh;
-        qh->urbp = urbp;
-
-        uhci_insert_tds_in_qh(qh, urb, UHCI_PTR_BREADTH);
+                        destination | uhci_explen(0), 0);
 
         /* Low-speed transfers get a different queue, and won't hog the bus.
          * Also, some devices enumerate better without FSBR; the easiest way
@@ -675,18 +615,13 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb, struct ur
          * isn't in the CONFIGURED state. */
         if (urb->dev->speed == USB_SPEED_LOW ||
                         urb->dev->state != USB_STATE_CONFIGURED)
-                skelqh = uhci->skel_ls_control_qh;
+                qh->skel = uhci->skel_ls_control_qh;
         else {
-                skelqh = uhci->skel_fs_control_qh;
+                qh->skel = uhci->skel_fs_control_qh;
                 uhci_inc_fsbr(uhci, urb);
         }
 
-        if (eurb)
-                uhci_append_queued_urb(uhci, eurb, urb);
-        else
-                uhci_insert_qh(uhci, skelqh, urb);
-
-        return -EINPROGRESS;
+        return 0;
 }
 
 /*
@@ -703,7 +638,7 @@ static int usb_control_retrigger_status(struct uhci_hcd *uhci, struct urb *urb)
         struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
         struct uhci_td *td;
 
-        urbp->short_control_packet = 1;
+        urbp->short_transfer = 1;
 
         td = list_entry(urbp->td_list.prev, struct uhci_td, list);
         urbp->qh->element = cpu_to_le32(td->dma_handle);
@@ -720,16 +655,14 @@ static int uhci_result_control(struct uhci_hcd *uhci, struct urb *urb)
         unsigned int status;
         int ret = 0;
 
-        if (list_empty(&urbp->td_list))
-                return -EINVAL;
-
         head = &urbp->td_list;
-
-        if (urbp->short_control_packet) {
+        if (urbp->short_transfer) {
                 tmp = head->prev;
                 goto status_stage;
         }
 
+        urb->actual_length = 0;
+
         tmp = head->next;
         td = list_entry(tmp, struct uhci_td, list);
 
@@ -742,8 +675,6 @@ static int uhci_result_control(struct uhci_hcd *uhci, struct urb *urb)
         if (status)
                 goto td_error;
 
-        urb->actual_length = 0;
-
         /* The rest of the TDs (but the last) are data */
         tmp = tmp->next;
         while (tmp != head && tmp->next != head) {
@@ -770,10 +701,7 @@ static int uhci_result_control(struct uhci_hcd *uhci, struct urb *urb)
                                 goto err;
                         }
 
-                        if (uhci_packetid(td_token(td)) == USB_PID_IN)
-                                return usb_control_retrigger_status(uhci, urb);
-                        else
-                                return 0;
+                        return usb_control_retrigger_status(uhci, urb);
                 }
         }
 
@@ -825,15 +753,15 @@ err:
 /*
  * Common submit for bulk and interrupt
  */
-static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, struct urb *eurb, struct uhci_qh *skelqh)
+static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb,
+                struct uhci_qh *qh)
 {
         struct uhci_td *td;
-        struct uhci_qh *qh;
         unsigned long destination, status;
-        int maxsze = usb_maxpacket(urb->dev, urb->pipe, usb_pipeout(urb->pipe));
+        int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize);
         int len = urb->transfer_buffer_length;
-        struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
         dma_addr_t data = urb->transfer_dma;
+        __le32 *plink, fake_link;
 
         if (len < 0)
                 return -EINVAL;
@@ -841,7 +769,8 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, struct urb
         /* The "pipe" thing contains the destination in bits 8--18 */
         destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
 
-        status = uhci_maxerr(3) | TD_CTRL_ACTIVE;
+        /* 3 errors */
+        status = TD_CTRL_ACTIVE | uhci_maxerr(3);
         if (urb->dev->speed == USB_SPEED_LOW)
                 status |= TD_CTRL_LS;
         if (usb_pipein(urb->pipe))
@@ -850,10 +779,11 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, struct urb
         /*
          * Build the DATA TDs
          */
+        plink = &fake_link;
         do {    /* Allow zero length packets */
                 int pktsze = maxsze;
 
-                if (pktsze >= len) {
+                if (len <= pktsze) {            /* The last packet */
                         pktsze = len;
                         if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
                                 status &= ~TD_CTRL_SPD;
@@ -862,12 +792,15 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, struct urb
                 td = uhci_alloc_td(uhci);
                 if (!td)
                         return -ENOMEM;
+                *plink = cpu_to_le32(td->dma_handle);
 
                 uhci_add_td_to_urb(urb, td);
-                uhci_fill_td(td, status, destination | uhci_explen(pktsze) |
+                uhci_fill_td(td, status,
+                        destination | uhci_explen(pktsze) |
                         (usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
                          usb_pipeout(urb->pipe)) << TD_TOKEN_TOGGLE_SHIFT),
                         data);
+                plink = &td->link;
 
                 data += pktsze;
                 len -= maxsze;
@@ -883,11 +816,13 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, struct urb
          * however, if transfer_length == 0, the zero packet was already
          * prepared above.
          */
-        if (usb_pipeout(urb->pipe) && (urb->transfer_flags & URB_ZERO_PACKET) &&
-            !len && urb->transfer_buffer_length) {
+        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)
                         return -ENOMEM;
+                *plink = cpu_to_le32(td->dma_handle);
 
                 uhci_add_td_to_urb(urb, td);
                 uhci_fill_td(td, status, destination | uhci_explen(0) |
@@ -905,24 +840,9 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, struct urb
          * 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_le32(TD_CTRL_IOC);
-
-        qh = uhci_alloc_qh(uhci);
-        if (!qh)
-                return -ENOMEM;
-
-        urbp->qh = qh;
-        qh->urbp = urbp;
+        td->status |= __constant_cpu_to_le32(TD_CTRL_IOC);
 
-        /* Always breadth first */
-        uhci_insert_tds_in_qh(qh, urb, UHCI_PTR_BREADTH);
-
-        if (eurb)
-                uhci_append_queued_urb(uhci, eurb, urb);
-        else
-                uhci_insert_qh(uhci, skelqh, urb);
-
-        return -EINPROGRESS;
+        return 0;
 }
 
 /*
@@ -954,8 +874,24 @@ static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
                         if (urb->transfer_flags & URB_SHORT_NOT_OK) {
                                 ret = -EREMOTEIO;
                                 goto err;
-                        } else
-                                return 0;
+                        }
+
+                        /*
+                         * This URB stopped short of its end.  We have to
+                         * fix up the toggles of the following URBs on the
+                         * queue and restart the queue.
+                         *
+                         * Do this only the first time we encounter the
+                         * short URB.
+                         */
+                        if (!urbp->short_transfer) {
+                                urbp->short_transfer = 1;
+                                uhci_fixup_toggles(urb);
+                                td = list_entry(urbp->td_list.prev,
+                                                struct uhci_td, list);
+                                urbp->qh->element = td->link;
+                        }
+                        break;
                 }
         }
 
@@ -988,7 +924,8 @@ err:
         return ret;
 }
 
-static inline int uhci_submit_bulk(struct uhci_hcd *uhci, struct urb *urb, struct urb *eurb)
+static inline int uhci_submit_bulk(struct uhci_hcd *uhci, struct urb *urb,
+                struct uhci_qh *qh)
 {
         int ret;
 
@@ -996,21 +933,22 @@ static inline int uhci_submit_bulk(struct uhci_hcd *uhci, struct urb *urb, struc
         if (urb->dev->speed == USB_SPEED_LOW)
                 return -EINVAL;
 
-        ret = uhci_submit_common(uhci, urb, eurb, uhci->skel_bulk_qh);
-        if (ret == -EINPROGRESS)
+        qh->skel = uhci->skel_bulk_qh;
+        ret = uhci_submit_common(uhci, urb, qh);
+        if (ret == 0)
                 uhci_inc_fsbr(uhci, urb);
-
         return ret;
 }
 
-static inline int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb, struct urb *eurb)
+static inline int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb,
+                struct uhci_qh *qh)
 {
-        /* USB 1.1 interrupt transfers only involve one packet per interval;
-         * that's the uhci_submit_common() "breadth first" policy.  Drivers
-         * can submit urbs of any length, but longer ones might need many
-         * intervals to complete.
+        /* 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.
          */
-        return uhci_submit_common(uhci, urb, eurb, uhci->skelqh[__interval_to_skel(urb->interval)]);
+        qh->skel = uhci->skelqh[__interval_to_skel(urb->interval)];
+        return uhci_submit_common(uhci, urb, qh);
 }
 
 /*
@@ -1072,11 +1010,12 @@ static int isochronous_find_start(struct uhci_hcd *uhci, struct urb *urb)
 /*
  * Isochronous transfers
  */
-static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb)
+static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb,
+                struct uhci_qh *qh)
 {
-        struct uhci_td *td;
+        struct uhci_td *td = NULL;      /* Since urb->number_of_packets > 0 */
         int i, ret, frame;
-        int status, destination;
+        unsigned long destination, status;
         struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 
         status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
@@ -1092,20 +1031,25 @@ static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb)
                         return -ENOMEM;
 
                 uhci_add_td_to_urb(urb, td);
-                uhci_fill_td(td, status, destination | uhci_explen(urb->iso_frame_desc[i].length),
-                        urb->transfer_dma + urb->iso_frame_desc[i].offset);
-
-                if (i + 1 >= urb->number_of_packets)
-                        td->status |= cpu_to_le32(TD_CTRL_IOC);
+                uhci_fill_td(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 |= __constant_cpu_to_le32(TD_CTRL_IOC);
+
+        qh->skel = uhci->skel_iso_qh;
+
+        /* Add the TDs to the frame list */
         frame = urb->start_frame;
         list_for_each_entry(td, &urbp->td_list, list) {
-                uhci_insert_td_frame_list(uhci, td, frame);
+                uhci_insert_td_in_frame_list(uhci, td, frame);
                 frame += urb->interval;
         }
 
-        return -EINPROGRESS;
+        return 0;
 }
 
 static int uhci_result_isochronous(struct uhci_hcd *uhci, struct urb *urb)
@@ -1139,80 +1083,67 @@ static int uhci_result_isochronous(struct uhci_hcd *uhci, struct urb *urb)
 
                 i++;
         }
-        unlink_isochronous_tds(uhci, urb);
 
         return ret;
 }
 
-static struct urb *uhci_find_urb_ep(struct uhci_hcd *uhci, struct urb *urb)
-{
-        struct urb_priv *up;
-
-        /* We don't match Isoc transfers since they are special */
-        if (usb_pipeisoc(urb->pipe))
-                return NULL;
-
-        list_for_each_entry(up, &uhci->urb_list, urb_list) {
-                struct urb *u = up->urb;
-
-                if (u->dev == urb->dev && u->status == -EINPROGRESS) {
-                        /* For control, ignore the direction */
-                        if (usb_pipecontrol(urb->pipe) &&
-                            (u->pipe & ~USB_DIR_IN) == (urb->pipe & ~USB_DIR_IN))
-                                return u;
-                        else if (u->pipe == urb->pipe)
-                                return u;
-                }
-        }
-
-        return NULL;
-}
-
 static int uhci_urb_enqueue(struct usb_hcd *hcd,
-                struct usb_host_endpoint *ep,
+                struct usb_host_endpoint *hep,
                 struct urb *urb, gfp_t mem_flags)
 {
         int ret;
         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
         unsigned long flags;
-        struct urb *eurb;
+        struct urb_priv *urbp;
+        struct uhci_qh *qh;
         int bustime;
 
         spin_lock_irqsave(&uhci->lock, flags);
 
         ret = urb->status;
         if (ret != -EINPROGRESS)                /* URB already unlinked! */
-                goto out;
+                goto done;
 
-        eurb = uhci_find_urb_ep(uhci, urb);
+        ret = -ENOMEM;
+        urbp = uhci_alloc_urb_priv(uhci, urb);
+        if (!urbp)
+                goto done;
 
-        if (!uhci_alloc_urb_priv(uhci, urb)) {
-                ret = -ENOMEM;
-                goto out;
+        if (hep->hcpriv)
+                qh = (struct uhci_qh *) hep->hcpriv;
+        else {
+                qh = uhci_alloc_qh(uhci, urb->dev, hep);
+                if (!qh)
+                        goto err_no_qh;
         }
+        urbp->qh = qh;
 
         switch (usb_pipetype(urb->pipe)) {
         case PIPE_CONTROL:
-                ret = uhci_submit_control(uhci, urb, eurb);
+                ret = uhci_submit_control(uhci, urb, qh);
+                break;
+        case PIPE_BULK:
+                ret = uhci_submit_bulk(uhci, urb, qh);
                 break;
         case PIPE_INTERRUPT:
-                if (!eurb) {
+                if (list_empty(&qh->queue)) {
                         bustime = usb_check_bandwidth(urb->dev, urb);
                         if (bustime < 0)
                                 ret = bustime;
                         else {
-                                ret = uhci_submit_interrupt(uhci, urb, eurb);
-                                if (ret == -EINPROGRESS)
+                                ret = uhci_submit_interrupt(uhci, urb, qh);
+                                if (ret == 0)
                                         usb_claim_bandwidth(urb->dev, urb, bustime, 0);
                         }
                 } else {        /* inherit from parent */
-                        urb->bandwidth = eurb->bandwidth;
-                        ret = uhci_submit_interrupt(uhci, urb, eurb);
+                        struct urb_priv *eurbp;
+
+                        eurbp = list_entry(qh->queue.prev, struct urb_priv,
+                                        node);
+                        urb->bandwidth = eurbp->urb->bandwidth;
+                        ret = uhci_submit_interrupt(uhci, urb, qh);
                 }
                 break;
-        case PIPE_BULK:
-                ret = uhci_submit_bulk(uhci, urb, eurb);
-                break;
         case PIPE_ISOCHRONOUS:
                 bustime = usb_check_bandwidth(urb->dev, urb);
                 if (bustime < 0) {
@@ -1220,22 +1151,59 @@ static int uhci_urb_enqueue(struct usb_hcd *hcd,
                         break;
                 }
 
-                ret = uhci_submit_isochronous(uhci, urb);
-                if (ret == -EINPROGRESS)
+                ret = uhci_submit_isochronous(uhci, urb, qh);
+                if (ret == 0)
                         usb_claim_bandwidth(urb->dev, urb, bustime, 1);
                 break;
         }
+        if (ret != 0)
+                goto err_submit_failed;
 
-        if (ret != -EINPROGRESS) {
-                /* Submit failed, so delete it from the urb_list */
-                struct urb_priv *urbp = urb->hcpriv;
+        /* Add this URB to the QH */
+        urbp->qh = qh;
+        list_add_tail(&urbp->node, &qh->queue);
+        list_add_tail(&urbp->urb_list, &uhci->urb_list);
 
-                list_del_init(&urbp->urb_list);
-                uhci_destroy_urb_priv(uhci, urb);
-        } else
-                ret = 0;
+        /* 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. */
+        if (qh->queue.next == &urbp->node)
+                uhci_activate_qh(uhci, qh);
+
+        /* If the QH is already active, we have a race with the hardware.
+         * This won't get fixed until dummy TDs are added. */
+        else if (qh->state == QH_STATE_ACTIVE) {
+
+                /* If the URB isn't first on its queue, adjust the link pointer
+                 * of the last TD in the previous URB. */
+                if (urbp->node.prev != &urbp->qh->queue) {
+                        struct urb_priv *purbp = list_entry(urbp->node.prev,
+                                        struct urb_priv, node);
+                        struct uhci_td *ptd = list_entry(purbp->td_list.prev,
+                                        struct uhci_td, list);
+                        struct uhci_td *td = list_entry(urbp->td_list.next,
+                                        struct uhci_td, list);
+
+                        ptd->link = cpu_to_le32(td->dma_handle);
+
+                }
+                if (qh_element(qh) == UHCI_PTR_TERM) {
+                        struct uhci_td *td = list_entry(urbp->td_list.next,
+                                        struct uhci_td, list);
+
+                        qh->element = cpu_to_le32(td->dma_handle);
+                }
+        }
+        goto done;
+
+err_submit_failed:
+        if (qh->state == QH_STATE_IDLE)
+                uhci_make_qh_idle(uhci, qh);    /* Reclaim unused QH */
 
-out:
+err_no_qh:
+        uhci_free_urb_priv(uhci, urbp);
+
+done:
         spin_unlock_irqrestore(&uhci->lock, flags);
         return ret;
 }
@@ -1245,119 +1213,115 @@ out:
  */
 static void uhci_transfer_result(struct uhci_hcd *uhci, struct urb *urb)
 {
-        int ret = -EINPROGRESS;
-        struct urb_priv *urbp;
-
-        spin_lock(&urb->lock);
-
-        urbp = (struct urb_priv *)urb->hcpriv;
-
-        if (urb->status != -EINPROGRESS)        /* URB already dequeued */
-                goto out;
+        int status;
+        int okay_to_giveback = 0;
+        struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 
         switch (usb_pipetype(urb->pipe)) {
         case PIPE_CONTROL:
-                ret = uhci_result_control(uhci, urb);
-                break;
-        case PIPE_BULK:
-        case PIPE_INTERRUPT:
-                ret = uhci_result_common(uhci, urb);
+                status = uhci_result_control(uhci, urb);
                 break;
         case PIPE_ISOCHRONOUS:
-                ret = uhci_result_isochronous(uhci, urb);
+                status = uhci_result_isochronous(uhci, urb);
+                break;
+        default:        /* PIPE_BULK or PIPE_INTERRUPT */
+                status = uhci_result_common(uhci, urb);
                 break;
         }
 
-        if (ret == -EINPROGRESS)
-                goto out;
-        urb->status = ret;
+        spin_lock(&urb->lock);
+        if (urb->status == -EINPROGRESS) {      /* Not yet dequeued */
+                if (status != -EINPROGRESS) {   /* URB has completed */
+                        urb->status = status;
+
+                        /* If the URB got a real error (as opposed to
+                         * simply being dequeued), we don't have to
+                         * unlink the QH.  Fix this later... */
+                        if (status < 0)
+                                uhci_unlink_qh(uhci, urbp->qh);
+                        else
+                                okay_to_giveback = 1;
+                }
+        } else {                                /* Already dequeued */
+                if (urbp->qh->state == QH_STATE_UNLINKING &&
+                                uhci->frame_number + uhci->is_stopped !=
+                                urbp->qh->unlink_frame)
+                        okay_to_giveback = 1;
+        }
+        spin_unlock(&urb->lock);
+        if (!okay_to_giveback)
+                return;
 
         switch (usb_pipetype(urb->pipe)) {
-        case PIPE_CONTROL:
-        case PIPE_BULK:
         case PIPE_ISOCHRONOUS:
                 /* Release bandwidth for Interrupt or Isoc. transfers */
                 if (urb->bandwidth)
                         usb_release_bandwidth(urb->dev, urb, 1);
-                uhci_unlink_generic(uhci, urb);
                 break;
         case PIPE_INTERRUPT:
                 /* Release bandwidth for Interrupt or Isoc. transfers */
                 /* Make sure we don't release if we have a queued URB */
-                if (list_empty(&urbp->queue_list) && urb->bandwidth)
+                if (list_empty(&urbp->qh->queue) && urb->bandwidth)
                         usb_release_bandwidth(urb->dev, urb, 0);
                 else
                         /* bandwidth was passed on to queued URB, */
                         /* so don't let usb_unlink_urb() release it */
                         urb->bandwidth = 0;
-                uhci_unlink_generic(uhci, urb);
+                /* Falls through */
+        case PIPE_BULK:
+                if (status < 0)
+                        uhci_fixup_toggles(urb);
+                break;
+        default:        /* PIPE_CONTROL */
                 break;
-        default:
-                dev_info(uhci_dev(uhci), "%s: unknown pipe type %d "
-                                "for urb %p\n",
-                                __FUNCTION__, usb_pipetype(urb->pipe), urb);
         }
 
-        /* Move it from uhci->urb_list to uhci->complete_list */
-        uhci_moveto_complete(uhci, urbp);
+        /* Take the URB's TDs off the hardware schedule */
+        uhci_remove_tds_from_schedule(uhci, urb, status);
 
-out:
-        spin_unlock(&urb->lock);
-}
-
-static void uhci_unlink_generic(struct uhci_hcd *uhci, struct urb *urb)
-{
-        struct list_head *head;
-        struct uhci_td *td;
-        struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
-        int prevactive = 0;
+        /* Take the URB off the QH's queue and see if the QH is now unused */
+        list_del_init(&urbp->node);
+        if (list_empty(&urbp->qh->queue))
+                uhci_unlink_qh(uhci, urbp->qh);
 
         uhci_dec_fsbr(uhci, urb);       /* Safe since it checks */
 
-        /*
-         * Now we need to find out what the last successful toggle was
-         * so we can update the local data toggle for the next transfer
-         *
-         * There are 2 ways the last successful completed TD is found:
-         *
-         * 1) The TD is NOT active and the actual length < expected length
-         * 2) The TD is NOT active and it's the last TD in the chain
-         *
-         * and a third way the first uncompleted TD is found:
-         *
-         * 3) The TD is active and the previous TD is NOT active
-         *
-         * Control and Isochronous ignore the toggle, so this is safe
-         * for all types
-         *
-         * FIXME: The toggle fixups won't be 100% reliable until we
-         * change over to using a single queue for each endpoint and
-         * stop the queue before unlinking.
-         */
-        head = &urbp->td_list;
-        list_for_each_entry(td, head, list) {
-                unsigned int ctrlstat = td_status(td);
+        /* Queue it for giving back */
+        list_move_tail(&urbp->urb_list, &uhci->complete_list);
+}
 
-                if (!(ctrlstat & TD_CTRL_ACTIVE) &&
-                                (uhci_actual_length(ctrlstat) <
-                                 uhci_expected_length(td_token(td)) ||
-                                td->list.next == head))
-                        usb_settoggle(urb->dev, uhci_endpoint(td_token(td)),
-                                uhci_packetout(td_token(td)),
-                                uhci_toggle(td_token(td)) ^ 1);
-                else if ((ctrlstat & TD_CTRL_ACTIVE) && !prevactive)
-                        usb_settoggle(urb->dev, uhci_endpoint(td_token(td)),
-                                uhci_packetout(td_token(td)),
-                                uhci_toggle(td_token(td)));
+/*
+ * Check out the QHs waiting to be fully unlinked
+ */
+static void uhci_scan_unlinking_qhs(struct uhci_hcd *uhci)
+{
+        struct uhci_qh *qh, *tmp;
 
-                prevactive = ctrlstat & TD_CTRL_ACTIVE;
-        }
+        list_for_each_entry_safe(qh, tmp, &uhci->skel_unlink_qh->node, node) {
 
-        uhci_delete_queued_urb(uhci, urb);
+                /* If the queue is empty and the QH is fully unlinked then
+                 * it can become IDLE. */
+                if (list_empty(&qh->queue)) {
+                        if (uhci->frame_number + uhci->is_stopped !=
+                                        qh->unlink_frame)
+                                uhci_make_qh_idle(uhci, qh);
 
-        /* The interrupt loop will reclaim the QHs */
-        uhci_remove_qh(uhci, urbp->qh);
-        urbp->qh = NULL;
+                /* If none of the QH's URBs have been dequeued then the QH
+                 * should be re-activated. */
+                } else {
+                        struct urb_priv *urbp;
+                        int any_dequeued = 0;
+
+                        list_for_each_entry(urbp, &qh->queue, node) {
+                                if (urbp->urb->status != -EINPROGRESS) {
+                                        any_dequeued = 1;
+                                        break;
+                                }
+                        }
+                        if (!any_dequeued)
+                                uhci_activate_qh(uhci, qh);
+                }
+        }
 }
 
 static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb)
@@ -1370,22 +1334,11 @@ static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb)
         urbp = urb->hcpriv;
         if (!urbp)                      /* URB was never linked! */
                 goto done;
-        list_del_init(&urbp->urb_list);
 
+        /* Remove Isochronous TDs from the frame list ASAP */
         if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
-                unlink_isochronous_tds(uhci, urb);
-        uhci_unlink_generic(uhci, urb);
-
-        uhci_get_current_frame_number(uhci);
-        if (uhci->frame_number + uhci->is_stopped != uhci->urb_remove_age) {
-                uhci_remove_pending_urbps(uhci);
-                uhci->urb_remove_age = uhci->frame_number;
-        }
-
-        /* If we're the first, set the next interrupt bit */
-        if (list_empty(&uhci->urb_remove_list))
-                uhci_set_next_interrupt(uhci);
-        list_add_tail(&urbp->urb_list, &uhci->urb_remove_list);
+                uhci_unlink_isochronous_tds(uhci, urb);
+        uhci_unlink_qh(uhci, urbp->qh);
 
 done:
         spin_unlock_irqrestore(&uhci->lock, flags);
@@ -1426,17 +1379,6 @@ static int uhci_fsbr_timeout(struct uhci_hcd *uhci, struct urb *urb)
         return 0;
 }
 
-static void uhci_free_pending_qhs(struct uhci_hcd *uhci)
-{
-        struct uhci_qh *qh, *tmp;
-
-        list_for_each_entry_safe(qh, tmp, &uhci->qh_remove_list, remove_list) {
-                list_del_init(&qh->remove_list);
-
-                uhci_free_qh(uhci, qh);
-        }
-}
-
 static void uhci_free_pending_tds(struct uhci_hcd *uhci)
 {
         struct uhci_td *td, *tmp;
@@ -1455,7 +1397,7 @@ __acquires(uhci->lock)
 {
         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
 
-        uhci_destroy_urb_priv(uhci, urb);
+        uhci_free_urb_priv(uhci, (struct urb_priv *) (urb->hcpriv));
 
         spin_unlock(&uhci->lock);
         usb_hcd_giveback_urb(hcd, urb, regs);
@@ -1474,13 +1416,6 @@ static void uhci_finish_completion(struct uhci_hcd *uhci, struct pt_regs *regs)
         }
 }
 
-static void uhci_remove_pending_urbps(struct uhci_hcd *uhci)
-{
-
-        /* Splice the urb_remove_list onto the end of the complete_list */
-        list_splice_init(&uhci->urb_remove_list, uhci->complete_list.prev);
-}
-
 /* Process events in the schedule, but only in one thread at a time */
 static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs)
 {
@@ -1498,12 +1433,8 @@ static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs)
         uhci_clear_next_interrupt(uhci);
         uhci_get_current_frame_number(uhci);
 
-        if (uhci->frame_number + uhci->is_stopped != uhci->qh_remove_age)
-                uhci_free_pending_qhs(uhci);
         if (uhci->frame_number + uhci->is_stopped != uhci->td_remove_age)
                 uhci_free_pending_tds(uhci);
-        if (uhci->frame_number + uhci->is_stopped != uhci->urb_remove_age)
-                uhci_remove_pending_urbps(uhci);
 
         /* Walk the list of pending URBs to see which ones completed
          * (must be _safe because uhci_transfer_result() dequeues URBs) */
@@ -1516,25 +1447,21 @@ static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs)
         uhci_finish_completion(uhci, regs);
 
         /* If the controller is stopped, we can finish these off right now */
-        if (uhci->is_stopped) {
-                uhci_free_pending_qhs(uhci);
+        if (uhci->is_stopped)
                 uhci_free_pending_tds(uhci);
-                uhci_remove_pending_urbps(uhci);
-        }
 
         if (uhci->need_rescan)
                 goto rescan;
         uhci->scan_in_progress = 0;
 
-        if (list_empty(&uhci->urb_remove_list) &&
-            list_empty(&uhci->td_remove_list) &&
-            list_empty(&uhci->qh_remove_list))
+        /* Check out the QHs waiting for unlinking */
+        uhci_scan_unlinking_qhs(uhci);
+
+        if (list_empty(&uhci->td_remove_list) &&
+                        list_empty(&uhci->skel_unlink_qh->node))
                 uhci_clear_next_interrupt(uhci);
         else
                 uhci_set_next_interrupt(uhci);
-
-        /* Wake up anyone waiting for an URB to complete */
-        wake_up_all(&uhci->waitqh);
 }
 
 static void check_fsbr(struct uhci_hcd *uhci)