[PATCH] UHCI: remove main list of URBs
authorAlan Stern <stern@rowland.harvard.edu>
Sat, 17 Dec 2005 23:02:38 +0000 (18:02 -0500)
committerGreg Kroah-Hartman <gregkh@suse.de>
Mon, 20 Mar 2006 22:49:57 +0000 (14:49 -0800)
As part of reorienting uhci-hcd away from URBs and toward endpoint
queues, this patch (as625) eliminates the driver's main list of URBs.
The list wsa used mainly in checking for URB completions; now the driver
goes through the list of active endpoints and checks the members of the
queues.

As a side effect, I had to remove the code that looks for FSBR timeouts.
For now, FSBR will remain on so long as any URBs on a full-speed control
or bulk queue request it, even if the queue isn't advancing.  A later
patch can add more intelligent handling.  This isn't a huge drawback;
it's pretty rare for an URB to get stuck for more than a fraction of a
second.  (And it will help the people trying to use those insane HP USB
devices.)

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/host/uhci-debug.c
drivers/usb/host/uhci-hcd.c
drivers/usb/host/uhci-hcd.h
drivers/usb/host/uhci-q.c

index 6814783..f2f5f8c 100644 (file)
@@ -114,7 +114,6 @@ static int uhci_show_urbp(struct urb_priv *urbp, char *buf, int len, int space)
        }
 
        out += sprintf(out, "%s", (urbp->fsbr ? " FSBR" : ""));
-       out += sprintf(out, "%s", (urbp->fsbr_timeout ? " FSBR_TO" : ""));
 
        if (urbp->urb->status != -EINPROGRESS)
                out += sprintf(out, " Status=%d", urbp->urb->status);
index 1ff4b88..9865f30 100644 (file)
@@ -491,8 +491,6 @@ static int uhci_start(struct usb_hcd *hcd)
        spin_lock_init(&uhci->lock);
 
        INIT_LIST_HEAD(&uhci->td_remove_list);
-       INIT_LIST_HEAD(&uhci->urb_list);
-       INIT_LIST_HEAD(&uhci->complete_list);
        INIT_LIST_HEAD(&uhci->idle_qh_list);
 
        init_waitqueue_head(&uhci->waitqh);
index c057956..7e96bef 100644 (file)
@@ -132,6 +132,10 @@ struct uhci_qh {
 
        unsigned int unlink_frame;      /* When the QH was unlinked */
        int state;                      /* QH_STATE_xxx; see above */
+
+       unsigned int initial_toggle:1;  /* Endpoint's current toggle value */
+       unsigned int needs_fixup:1;     /* Must fix the TD toggle values */
+       unsigned int is_stopped:1;      /* Queue was stopped by an error */
 } __attribute__((aligned(16)));
 
 /*
@@ -384,6 +388,7 @@ struct uhci_hcd {
 
        struct uhci_td *term_td;        /* Terminating TD, see UHCI bug */
        struct uhci_qh *skelqh[UHCI_NUM_SKELQH];        /* Skeleton QHs */
+       struct uhci_qh *next_qh;        /* Next QH to scan */
 
        spinlock_t lock;
 
@@ -413,16 +418,10 @@ struct uhci_hcd {
        unsigned long resuming_ports;
        unsigned long ports_timeout;            /* Time to stop signalling */
 
-       /* Main list of URBs currently controlled by this HC */
-       struct list_head urb_list;
-
        /* List of TDs that are done, but waiting to be freed (race) */
        struct list_head td_remove_list;
        unsigned int td_remove_age;             /* Age in frames */
 
-       /* List of URBs awaiting completion callback */
-       struct list_head complete_list;
-
        struct list_head idle_qh_list;          /* Where the idle QHs live */
 
        int rh_numports;                        /* Number of root-hub ports */
@@ -448,7 +447,6 @@ static inline struct usb_hcd *uhci_to_hcd(struct uhci_hcd *uhci)
  *     Private per-URB data
  */
 struct urb_priv {
-       struct list_head urb_list;
        struct list_head node;          /* Node in the QH's urbp list */
 
        struct urb *urb;
@@ -456,10 +454,7 @@ struct urb_priv {
        struct uhci_qh *qh;             /* QH for this URB */
        struct list_head td_list;
 
-       unsigned long fsbrtime;         /* In jiffies */
-
        unsigned fsbr : 1;              /* URB turned on FSBR */
-       unsigned fsbr_timeout : 1;      /* URB timed out on FSBR */
        unsigned short_transfer : 1;    /* URB got a short transfer, no
                                         * need to rescan */
 };
index c419418..44bba9a 100644 (file)
@@ -151,53 +151,6 @@ static void uhci_unlink_isochronous_tds(struct uhci_hcd *uhci, struct urb *urb)
        wmb();
 }
 
-/*
- * Remove an URB's TDs from the hardware schedule
- */
-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;
-
-       /* Isochronous TDs get unlinked directly from the frame list */
-       if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
-               uhci_unlink_isochronous_tds(uhci, urb);
-               return;
-       }
-
-       /* 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;
-       }
-
-       /* 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,
                struct usb_device *udev, struct usb_host_endpoint *hep)
 {
@@ -251,6 +204,90 @@ static void uhci_free_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 }
 
 /*
+ * When the currently executing URB is dequeued, save its current toggle value
+ */
+static void uhci_save_toggle(struct uhci_qh *qh, struct urb *urb)
+{
+       struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
+       struct uhci_td *td;
+
+       /* 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 ||
+                               qh->queue.next != &urbp->node)
+               return;
+       qh->element = UHCI_PTR_TERM;
+
+       /* Only bulk and interrupt pipes have to worry about toggles */
+       if (!(usb_pipetype(urb->pipe) == PIPE_BULK ||
+                       usb_pipetype(urb->pipe) == PIPE_INTERRUPT))
+               return;
+
+       /* Find the first active TD; that's the device's toggle state */
+       list_for_each_entry(td, &urbp->td_list, list) {
+               if (td_status(td) & TD_CTRL_ACTIVE) {
+                       qh->needs_fixup = 1;
+                       qh->initial_toggle = uhci_toggle(td_token(td));
+                       return;
+               }
+       }
+
+       WARN_ON(1);
+}
+
+/*
+ * 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_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)
+               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. */
+       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(td)) == toggle) {
+                       td = list_entry(urbp->td_list.next, struct uhci_td,
+                                       list);
+                       toggle = uhci_toggle(td_token(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 ^= __constant_cpu_to_le32(
+                                                       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;
+}
+
+/*
  * Put a QH on the schedule in both hardware and software
  */
 static void uhci_activate_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
@@ -276,6 +313,9 @@ static void uhci_activate_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 
        /* Move the QH from its old list to the end of the appropriate
         * skeleton's list */
+       if (qh == uhci->next_qh)
+               uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
+                               node);
        list_move_tail(&qh->node, &qh->skel->node);
 
        /* Link it into the schedule */
@@ -310,6 +350,9 @@ static void uhci_unlink_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
                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);
 }
 
@@ -323,6 +366,9 @@ 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;
 
@@ -344,11 +390,9 @@ static inline struct urb_priv *uhci_alloc_urb_priv(struct uhci_hcd *uhci,
 
        urbp->urb = urb;
        urb->hcpriv = urbp;
-       urbp->fsbrtime = jiffies;
        
        INIT_LIST_HEAD(&urbp->node);
        INIT_LIST_HEAD(&urbp->td_list);
-       INIT_LIST_HEAD(&urbp->urb_list);
 
        return urbp;
 }
@@ -373,9 +417,6 @@ static void uhci_free_urb_priv(struct uhci_hcd *uhci,
 {
        struct uhci_td *td, *tmp;
 
-       if (!list_empty(&urbp->urb_list))
-               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);
@@ -453,71 +494,6 @@ 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,
@@ -765,6 +741,9 @@ err:
                }
        }
 
+       /* Note that the queue has stopped */
+       urbp->qh->element = UHCI_PTR_TERM;
+       urbp->qh->is_stopped = 1;
        return ret;
 }
 
@@ -927,7 +906,10 @@ static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
                         */
                        if (!urbp->short_transfer) {
                                urbp->short_transfer = 1;
-                               uhci_fixup_toggles(urb);
+                               urbp->qh->initial_toggle =
+                                               uhci_toggle(td_token(td)) ^ 1;
+                               uhci_fixup_toggles(urbp->qh, 1);
+
                                td = list_entry(urbp->td_list.prev,
                                                struct uhci_td, list);
                                urbp->qh->element = td->link;
@@ -962,6 +944,13 @@ err:
                }
        }
 #endif
+
+       /* Note that the queue has stopped and save the next toggle value */
+       urbp->qh->element = UHCI_PTR_TERM;
+       urbp->qh->is_stopped = 1;
+       urbp->qh->needs_fixup = 1;
+       urbp->qh->initial_toggle = uhci_toggle(td_token(td)) ^
+                       (ret == -EREMOTEIO);
        return ret;
 }
 
@@ -995,76 +984,39 @@ static inline int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb,
 /*
  * Isochronous transfers
  */
-static int isochronous_find_limits(struct uhci_hcd *uhci, struct urb *urb, unsigned int *start, unsigned int *end)
-{
-       struct urb *last_urb = NULL;
-       struct urb_priv *up;
-       int ret = 0;
-
-       list_for_each_entry(up, &uhci->urb_list, urb_list) {
-               struct urb *u = up->urb;
-
-               /* look for pending URBs with identical pipe handle */
-               if ((urb->pipe == u->pipe) && (urb->dev == u->dev) &&
-                   (u->status == -EINPROGRESS) && (u != urb)) {
-                       if (!last_urb)
-                               *start = u->start_frame;
-                       last_urb = u;
-               }
-       }
-
-       if (last_urb) {
-               *end = (last_urb->start_frame + last_urb->number_of_packets *
-                               last_urb->interval) & (UHCI_NUMFRAMES-1);
-               ret = 0;
-       } else
-               ret = -1;       /* no previous urb found */
-
-       return ret;
-}
-
-static int isochronous_find_start(struct uhci_hcd *uhci, struct urb *urb)
+static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb,
+               struct uhci_qh *qh)
 {
-       int limits;
-       unsigned int start = 0, end = 0;
+       struct uhci_td *td = NULL;      /* Since urb->number_of_packets > 0 */
+       int i, frame;
+       unsigned long destination, status;
+       struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 
        if (urb->number_of_packets > 900)       /* 900? Why? */
                return -EFBIG;
 
-       limits = isochronous_find_limits(uhci, urb, &start, &end);
+       status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
+       destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
 
+       /* Figure out the starting frame number */
        if (urb->transfer_flags & URB_ISO_ASAP) {
-               if (limits) {
+               if (list_empty(&qh->queue)) {
                        uhci_get_current_frame_number(uhci);
-                       urb->start_frame = (uhci->frame_number + 10)
-                                       & (UHCI_NUMFRAMES - 1);
-               } else
-                       urb->start_frame = end;
+                       urb->start_frame = (uhci->frame_number + 10);
+
+               } else {                /* Go right after the last one */
+                       struct urb *last_urb;
+
+                       last_urb = list_entry(qh->queue.prev,
+                                       struct urb_priv, node)->urb;
+                       urb->start_frame = (last_urb->start_frame +
+                                       last_urb->number_of_packets *
+                                       last_urb->interval);
+               }
        } else {
-               urb->start_frame &= (UHCI_NUMFRAMES - 1);
                /* FIXME: Sanity check */
        }
-
-       return 0;
-}
-
-/*
- * 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, ret, frame;
-       unsigned long destination, status;
-       struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
-
-       status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
-       destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
-
-       ret = isochronous_find_start(uhci, urb);
-       if (ret)
-               return ret;
+       urb->start_frame &= (UHCI_NUMFRAMES - 1);
 
        for (i = 0; i < urb->number_of_packets; i++) {
                td = uhci_alloc_td(uhci);
@@ -1203,7 +1155,6 @@ static int uhci_urb_enqueue(struct usb_hcd *hcd,
        /* 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);
 
        /* 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
@@ -1224,49 +1175,66 @@ done:
        return ret;
 }
 
+static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb)
+{
+       struct uhci_hcd *uhci = hcd_to_uhci(hcd);
+       unsigned long flags;
+       struct urb_priv *urbp;
+
+       spin_lock_irqsave(&uhci->lock, flags);
+       urbp = urb->hcpriv;
+       if (!urbp)                      /* URB was never linked! */
+               goto done;
+
+       /* Remove Isochronous TDs from the frame list ASAP */
+       if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
+               uhci_unlink_isochronous_tds(uhci, urb);
+       uhci_unlink_qh(uhci, urbp->qh);
+
+done:
+       spin_unlock_irqrestore(&uhci->lock, flags);
+       return 0;
+}
+
 /*
- * Return the result of a transfer
+ * Finish unlinking an URB and give it back
  */
-static void uhci_transfer_result(struct uhci_hcd *uhci, struct urb *urb)
+static void uhci_giveback_urb(struct uhci_hcd *uhci, struct uhci_qh *qh,
+               struct urb *urb, struct pt_regs *regs)
+__releases(uhci->lock)
+__acquires(uhci->lock)
 {
-       int status;
-       int okay_to_giveback = 0;
        struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 
-       switch (usb_pipetype(urb->pipe)) {
-       case PIPE_CONTROL:
-               status = uhci_result_control(uhci, urb);
-               break;
-       case PIPE_ISOCHRONOUS:
-               status = uhci_result_isochronous(uhci, urb);
-               break;
-       default:        /* PIPE_BULK or PIPE_INTERRUPT */
-               status = uhci_result_common(uhci, urb);
-               break;
-       }
+       /* Isochronous TDs get unlinked directly from the frame list */
+       if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
+               uhci_unlink_isochronous_tds(uhci, urb);
 
-       spin_lock(&urb->lock);
-       if (urb->status == -EINPROGRESS) {      /* Not yet dequeued */
-               if (status != -EINPROGRESS) {   /* URB has completed */
-                       urb->status = status;
+       /* If the URB isn't first on its queue, adjust the link pointer
+        * of the last TD in the previous URB. */
+       else if (qh->queue.next != &urbp->node) {
+               struct urb_priv *purbp;
+               struct uhci_td *ptd, *ltd;
 
-                       /* 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;
+               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;
        }
-       spin_unlock(&urb->lock);
-       if (!okay_to_giveback)
-               return;
+
+       /* 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_dec_fsbr(uhci, urb);       /* Safe since it checks */
+       uhci_free_urb_priv(uhci, urbp);
 
        switch (usb_pipetype(urb->pipe)) {
        case PIPE_ISOCHRONOUS:
@@ -1277,122 +1245,107 @@ static void uhci_transfer_result(struct uhci_hcd *uhci, struct urb *urb)
        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->qh->queue) && urb->bandwidth)
+               if (list_empty(&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;
-               /* Falls through */
-       case PIPE_BULK:
-               if (status < 0)
-                       uhci_fixup_toggles(urb);
-               break;
-       default:        /* PIPE_CONTROL */
                break;
        }
 
-       /* Take the URB's TDs off the hardware schedule */
-       uhci_remove_tds_from_schedule(uhci, urb, status);
-
-       /* 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);
+       spin_unlock(&uhci->lock);
+       usb_hcd_giveback_urb(uhci_to_hcd(uhci), urb, regs);
+       spin_lock(&uhci->lock);
 
-       uhci_dec_fsbr(uhci, urb);       /* Safe since it checks */
+       /* 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);
 
-       /* Queue it for giving back */
-       list_move_tail(&urbp->urb_list, &uhci->complete_list);
+               /* Bandwidth stuff not yet implemented */
+       }
 }
 
 /*
- * Check out the QHs waiting to be fully unlinked
+ * Scan the URBs in a QH's queue
  */
-static void uhci_scan_unlinking_qhs(struct uhci_hcd *uhci)
-{
-       struct uhci_qh *qh, *tmp;
+#define QH_FINISHED_UNLINKING(qh)                      \
+               (qh->state == QH_STATE_UNLINKING &&     \
+               uhci->frame_number + uhci->is_stopped != qh->unlink_frame)
 
-       list_for_each_entry_safe(qh, tmp, &uhci->skel_unlink_qh->node, node) {
-
-               /* 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);
-
-               /* 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)
+static void uhci_scan_qh(struct uhci_hcd *uhci, struct uhci_qh *qh,
+               struct pt_regs *regs)
 {
-       struct uhci_hcd *uhci = hcd_to_uhci(hcd);
-       unsigned long flags;
        struct urb_priv *urbp;
+       struct urb *urb;
+       int status;
 
-       spin_lock_irqsave(&uhci->lock, flags);
-       urbp = urb->hcpriv;
-       if (!urbp)                      /* URB was never linked! */
-               goto done;
+       while (!list_empty(&qh->queue)) {
+               urbp = list_entry(qh->queue.next, struct urb_priv, node);
+               urb = urbp->urb;
 
-       /* Remove Isochronous TDs from the frame list ASAP */
-       if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
-               uhci_unlink_isochronous_tds(uhci, urb);
-       uhci_unlink_qh(uhci, urbp->qh);
+               switch (usb_pipetype(urb->pipe)) {
+               case PIPE_CONTROL:
+                       status = uhci_result_control(uhci, urb);
+                       break;
+               case PIPE_ISOCHRONOUS:
+                       status = uhci_result_isochronous(uhci, urb);
+                       break;
+               default:        /* PIPE_BULK or PIPE_INTERRUPT */
+                       status = uhci_result_common(uhci, urb);
+                       break;
+               }
+               if (status == -EINPROGRESS)
+                       break;
 
-done:
-       spin_unlock_irqrestore(&uhci->lock, flags);
-       return 0;
-}
+               spin_lock(&urb->lock);
+               if (urb->status == -EINPROGRESS)        /* Not dequeued */
+                       urb->status = status;
+               else
+                       status = -ECONNRESET;
+               spin_unlock(&urb->lock);
 
-static int uhci_fsbr_timeout(struct uhci_hcd *uhci, struct urb *urb)
-{
-       struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
-       struct list_head *head;
-       struct uhci_td *td;
-       int count = 0;
+               /* Dequeued but completed URBs can't be given back unless
+                * the QH is stopped or has finished unlinking. */
+               if (status == -ECONNRESET &&
+                               !(qh->is_stopped || QH_FINISHED_UNLINKING(qh)))
+                       return;
 
-       uhci_dec_fsbr(uhci, urb);
+               uhci_giveback_urb(uhci, qh, urb, regs);
+               if (qh->is_stopped)
+                       break;
+       }
 
-       urbp->fsbr_timeout = 1;
+       /* If the QH is neither stopped nor finished unlinking (normal case),
+        * our work here is done. */
+ restart:
+       if (!(qh->is_stopped || QH_FINISHED_UNLINKING(qh)))
+               return;
 
-       /*
-        * Ideally we would want to fix qh->element as well, but it's
-        * read/write by the HC, so that can introduce a race. It's not
-        * really worth the hassle
-        */
+       /* Otherwise give back each of the dequeued URBs */
+       list_for_each_entry(urbp, &qh->queue, node) {
+               urb = urbp->urb;
+               if (urb->status != -EINPROGRESS) {
+                       uhci_save_toggle(qh, urb);
+                       uhci_giveback_urb(uhci, qh, urb, regs);
+                       goto restart;
+               }
+       }
+       qh->is_stopped = 0;
 
-       head = &urbp->td_list;
-       list_for_each_entry(td, head, list) {
-               /*
-                * Make sure we don't do the last one (since it'll have the
-                * TERM bit set) as well as we skip every so many TDs to
-                * make sure it doesn't hog the bandwidth
-                */
-               if (td->list.next != head && (count % DEPTH_INTERVAL) ==
-                               (DEPTH_INTERVAL - 1))
-                       td->link |= UHCI_PTR_DEPTH;
-
-               count++;
+       /* 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(qh, 0);
+               uhci_activate_qh(uhci, qh);
        }
 
-       return 0;
+       /* 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);
 }
 
 static void uhci_free_pending_tds(struct uhci_hcd *uhci)
@@ -1406,36 +1359,13 @@ static void uhci_free_pending_tds(struct uhci_hcd *uhci)
        }
 }
 
-static void
-uhci_finish_urb(struct usb_hcd *hcd, struct urb *urb, struct pt_regs *regs)
-__releases(uhci->lock)
-__acquires(uhci->lock)
-{
-       struct uhci_hcd *uhci = hcd_to_uhci(hcd);
-
-       uhci_free_urb_priv(uhci, (struct urb_priv *) (urb->hcpriv));
-
-       spin_unlock(&uhci->lock);
-       usb_hcd_giveback_urb(hcd, urb, regs);
-       spin_lock(&uhci->lock);
-}
-
-static void uhci_finish_completion(struct uhci_hcd *uhci, struct pt_regs *regs)
-{
-       struct urb_priv *urbp, *tmp;
-
-       list_for_each_entry_safe(urbp, tmp, &uhci->complete_list, urb_list) {
-               struct urb *urb = urbp->urb;
-
-               list_del_init(&urbp->urb_list);
-               uhci_finish_urb(uhci_to_hcd(uhci), urb, regs);
-       }
-}
-
-/* Process events in the schedule, but only in one thread at a time */
+/*
+ * 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)
 {
-       struct urb_priv *urbp, *tmp;
+       int i;
+       struct uhci_qh *qh;
 
        /* Don't allow re-entrant calls */
        if (uhci->scan_in_progress) {
@@ -1452,26 +1382,24 @@ static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs)
        if (uhci->frame_number + uhci->is_stopped != uhci->td_remove_age)
                uhci_free_pending_tds(uhci);
 
-       /* Walk the list of pending URBs to see which ones completed
-        * (must be _safe because uhci_transfer_result() dequeues URBs) */
-       list_for_each_entry_safe(urbp, tmp, &uhci->urb_list, urb_list) {
-               struct urb *urb = urbp->urb;
-
-               /* Checks the status and does all of the magic necessary */
-               uhci_transfer_result(uhci, urb);
+       /* 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);
+                       uhci_scan_qh(uhci, qh, 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_tds(uhci);
 
        if (uhci->need_rescan)
                goto rescan;
        uhci->scan_in_progress = 0;
 
-       /* Check out the QHs waiting for unlinking */
-       uhci_scan_unlinking_qhs(uhci);
+       /* If the controller is stopped, we can finish these off right now */
+       if (uhci->is_stopped)
+               uhci_free_pending_tds(uhci);
 
        if (list_empty(&uhci->td_remove_list) &&
                        list_empty(&uhci->skel_unlink_qh->node))
@@ -1482,19 +1410,8 @@ static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs)
 
 static void check_fsbr(struct uhci_hcd *uhci)
 {
-       struct urb_priv *up;
-
-       list_for_each_entry(up, &uhci->urb_list, urb_list) {
-               struct urb *u = up->urb;
-
-               spin_lock(&u->lock);
-
-               /* Check if the FSBR timed out */
-               if (up->fsbr && !up->fsbr_timeout && time_after_eq(jiffies, up->fsbrtime + IDLE_TIMEOUT))
-                       uhci_fsbr_timeout(uhci, u);
-
-               spin_unlock(&u->lock);
-       }
+       /* For now, don't scan URBs for FSBR timeouts.
+        * Add it back in later... */
 
        /* Really disable FSBR */
        if (!uhci->fsbr && uhci->fsbrtimeout && time_after_eq(jiffies, uhci->fsbrtimeout)) {