[PATCH] UHCI: use one QH per endpoint, not per URB
Alan Stern [Sat, 17 Dec 2005 22:58:46 +0000 (17:58 -0500)]
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>

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 5832953..3faccbd 100644 (file)
@@ -90,13 +90,60 @@ static int uhci_show_td(struct uhci_td *td, char *buf, int len, int space)
        return out - buf;
 }
 
-static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space)
+static int uhci_show_urbp(struct urb_priv *urbp, char *buf, int len, int space)
 {
        char *out = buf;
-       struct urb_priv *urbp;
-       struct list_head *head, *tmp;
        struct uhci_td *td;
-       int i = 0, checked = 0, prevactive = 0;
+       int i, nactive, ninactive;
+
+       if (len < 200)
+               return 0;
+
+       out += sprintf(out, "urb_priv [%p] ", urbp);
+       out += sprintf(out, "urb [%p] ", urbp->urb);
+       out += sprintf(out, "qh [%p] ", urbp->qh);
+       out += sprintf(out, "Dev=%d ", usb_pipedevice(urbp->urb->pipe));
+       out += sprintf(out, "EP=%x(%s) ", usb_pipeendpoint(urbp->urb->pipe),
+                       (usb_pipein(urbp->urb->pipe) ? "IN" : "OUT"));
+
+       switch (usb_pipetype(urbp->urb->pipe)) {
+       case PIPE_ISOCHRONOUS: out += sprintf(out, "ISO"); break;
+       case PIPE_INTERRUPT: out += sprintf(out, "INT"); break;
+       case PIPE_BULK: out += sprintf(out, "BLK"); break;
+       case PIPE_CONTROL: out += sprintf(out, "CTL"); break;
+       }
+
+       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);
+       out += sprintf(out, "\n");
+
+       i = nactive = ninactive = 0;
+       list_for_each_entry(td, &urbp->td_list, list) {
+               if (++i <= 10 || debug > 2) {
+                       out += sprintf(out, "%*s%d: ", space + 2, "", i);
+                       out += uhci_show_td(td, out, len - (out - buf), 0);
+               } else {
+                       if (td_status(td) & TD_CTRL_ACTIVE)
+                               ++nactive;
+                       else
+                               ++ninactive;
+               }
+       }
+       if (nactive + ninactive > 0)
+               out += sprintf(out, "%*s[skipped %d inactive and %d active "
+                               "TDs]\n",
+                               space, "", ninactive, nactive);
+
+       return out - buf;
+}
+
+static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space)
+{
+       char *out = buf;
+       int i, nurbs;
        __le32 element = qh_element(qh);
 
        /* Try to make sure there's enough memory */
@@ -118,86 +165,36 @@ static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space)
        if (!(element & ~(UHCI_PTR_QH | UHCI_PTR_DEPTH)))
                out += sprintf(out, "%*s  Element is NULL (bug?)\n", space, "");
 
-       if (!qh->urbp) {
-               out += sprintf(out, "%*s  urbp == NULL\n", space, "");
-               goto out;
-       }
-
-       urbp = qh->urbp;
-
-       head = &urbp->td_list;
-       tmp = head->next;
-
-       td = list_entry(tmp, struct uhci_td, list);
-
-       if (cpu_to_le32(td->dma_handle) != (element & ~UHCI_PTR_BITS))
-               out += sprintf(out, "%*s Element != First TD\n", space, "");
-
-       while (tmp != head) {
-               struct uhci_td *td = list_entry(tmp, struct uhci_td, list);
-
-               tmp = tmp->next;
-
-               out += sprintf(out, "%*s%d: ", space + 2, "", i++);
-               out += uhci_show_td(td, out, len - (out - buf), 0);
-
-               if (i > 10 && !checked && prevactive && tmp != head &&
-                   debug <= 2) {
-                       struct list_head *ntmp = tmp;
-                       struct uhci_td *ntd = td;
-                       int active = 1, ni = i;
-
-                       checked = 1;
-
-                       while (ntmp != head && ntmp->next != head && active) {
-                               ntd = list_entry(ntmp, struct uhci_td, list);
-
-                               ntmp = ntmp->next;
-
-                               active = td_status(ntd) & TD_CTRL_ACTIVE;
-
-                               ni++;
-                       }
-
-                       if (active && ni > i) {
-                               out += sprintf(out, "%*s[skipped %d active TDs]\n", space, "", ni - i);
-                               tmp = ntmp;
-                               td = ntd;
-                               i = ni;
-                       }
+       if (list_empty(&qh->queue)) {
+               out += sprintf(out, "%*s  queue is empty\n", space, "");
+       } else {
+               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);
+
+               if (cpu_to_le32(td->dma_handle) != (element & ~UHCI_PTR_BITS))
+                       out += sprintf(out, "%*s Element != First TD\n",
+                                       space, "");
+               i = nurbs = 0;
+               list_for_each_entry(urbp, &qh->queue, node) {
+                       if (++i <= 10)
+                               out += uhci_show_urbp(urbp, out,
+                                               len - (out - buf), space + 2);
+                       else
+                               ++nurbs;
                }
-
-               prevactive = td_status(td) & TD_CTRL_ACTIVE;
-       }
-
-       if (list_empty(&urbp->queue_list) || urbp->queued)
-               goto out;
-
-       out += sprintf(out, "%*sQueued QHs:\n", -space, "--");
-
-       head = &urbp->queue_list;
-       tmp = head->next;
-
-       while (tmp != head) {
-               struct urb_priv *nurbp = list_entry(tmp, struct urb_priv,
-                                               queue_list);
-               tmp = tmp->next;
-
-               out += uhci_show_qh(nurbp->qh, out, len - (out - buf), space);
+               if (nurbs > 0)
+                       out += sprintf(out, "%*s Skipped %d URBs\n",
+                                       space, "", nurbs);
        }
 
-out:
        return out - buf;
 }
 
-#define show_frame_num()       \
-       if (!shown) {           \
-         shown = 1;            \
-         out += sprintf(out, "- Frame %d\n", i); \
-       }
-
 #ifdef CONFIG_PROC_FS
 static const char * const qh_names[] = {
+  "skel_unlink_qh", "skel_iso_qh",
   "skel_int128_qh", "skel_int64_qh",
   "skel_int32_qh", "skel_int16_qh",
   "skel_int8_qh", "skel_int4_qh",
@@ -206,12 +203,6 @@ static const char * const qh_names[] = {
   "skel_bulk_qh", "skel_term_qh"
 };
 
-#define show_qh_name()         \
-       if (!shown) {           \
-         shown = 1;            \
-         out += sprintf(out, "- %s\n", qh_names[i]); \
-       }
-
 static int uhci_show_sc(int port, unsigned short status, char *buf, int len)
 {
        char *out = buf;
@@ -321,139 +312,29 @@ static int uhci_show_status(struct uhci_hcd *uhci, char *buf, int len)
        return out - buf;
 }
 
-static int uhci_show_urbp(struct uhci_hcd *uhci, struct urb_priv *urbp, char *buf, int len)
-{
-       struct list_head *tmp;
-       char *out = buf;
-       int count = 0;
-
-       if (len < 200)
-               return 0;
-
-       out += sprintf(out, "urb_priv [%p] ", urbp);
-       out += sprintf(out, "urb [%p] ", urbp->urb);
-       out += sprintf(out, "qh [%p] ", urbp->qh);
-       out += sprintf(out, "Dev=%d ", usb_pipedevice(urbp->urb->pipe));
-       out += sprintf(out, "EP=%x(%s) ", usb_pipeendpoint(urbp->urb->pipe), (usb_pipein(urbp->urb->pipe) ? "IN" : "OUT"));
-
-       switch (usb_pipetype(urbp->urb->pipe)) {
-       case PIPE_ISOCHRONOUS: out += sprintf(out, "ISO "); break;
-       case PIPE_INTERRUPT: out += sprintf(out, "INT "); break;
-       case PIPE_BULK: out += sprintf(out, "BLK "); break;
-       case PIPE_CONTROL: out += sprintf(out, "CTL "); break;
-       }
-
-       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);
-       //out += sprintf(out, "FSBRtime=%lx ",urbp->fsbrtime);
-
-       count = 0;
-       list_for_each(tmp, &urbp->td_list)
-               count++;
-       out += sprintf(out, "TDs=%d ",count);
-
-       if (urbp->queued)
-               out += sprintf(out, "queued\n");
-       else {
-               count = 0;
-               list_for_each(tmp, &urbp->queue_list)
-                       count++;
-               out += sprintf(out, "queued URBs=%d\n", count);
-       }
-
-       return out - buf;
-}
-
-static int uhci_show_lists(struct uhci_hcd *uhci, char *buf, int len)
-{
-       char *out = buf;
-       struct list_head *head, *tmp;
-       int count;
-
-       out += sprintf(out, "Main list URBs:");
-       if (list_empty(&uhci->urb_list))
-               out += sprintf(out, " Empty\n");
-       else {
-               out += sprintf(out, "\n");
-               count = 0;
-               head = &uhci->urb_list;
-               tmp = head->next;
-               while (tmp != head) {
-                       struct urb_priv *urbp = list_entry(tmp, struct urb_priv, urb_list);
-
-                       out += sprintf(out, "  %d: ", ++count);
-                       out += uhci_show_urbp(uhci, urbp, out, len - (out - buf));
-                       tmp = tmp->next;
-               }
-       }
-
-       out += sprintf(out, "Remove list URBs:");
-       if (list_empty(&uhci->urb_remove_list))
-               out += sprintf(out, " Empty\n");
-       else {
-               out += sprintf(out, "\n");
-               count = 0;
-               head = &uhci->urb_remove_list;
-               tmp = head->next;
-               while (tmp != head) {
-                       struct urb_priv *urbp = list_entry(tmp, struct urb_priv, urb_list);
-
-                       out += sprintf(out, "  %d: ", ++count);
-                       out += uhci_show_urbp(uhci, urbp, out, len - (out - buf));
-                       tmp = tmp->next;
-               }
-       }
-
-       out += sprintf(out, "Complete list URBs:");
-       if (list_empty(&uhci->complete_list))
-               out += sprintf(out, " Empty\n");
-       else {
-               out += sprintf(out, "\n");
-               count = 0;
-               head = &uhci->complete_list;
-               tmp = head->next;
-               while (tmp != head) {
-                       struct urb_priv *urbp = list_entry(tmp, struct urb_priv, urb_list);
-
-                       out += sprintf(out, "  %d: ", ++count);
-                       out += uhci_show_urbp(uhci, urbp, out, len - (out - buf));
-                       tmp = tmp->next;
-               }
-       }
-
-       return out - buf;
-}
-
 static int uhci_sprint_schedule(struct uhci_hcd *uhci, char *buf, int len)
 {
-       unsigned long flags;
        char *out = buf;
        int i, j;
        struct uhci_qh *qh;
        struct uhci_td *td;
        struct list_head *tmp, *head;
 
-       spin_lock_irqsave(&uhci->lock, flags);
-
        out += uhci_show_root_hub_state(uhci, out, len - (out - buf));
        out += sprintf(out, "HC status\n");
        out += uhci_show_status(uhci, out, len - (out - buf));
+       if (debug <= 1)
+               return out - buf;
 
        out += sprintf(out, "Frame List\n");
        for (i = 0; i < UHCI_NUMFRAMES; ++i) {
-               int shown = 0;
                td = uhci->frame_cpu[i];
                if (!td)
                        continue;
 
-               if (td->dma_handle != (dma_addr_t)uhci->frame[i]) {
-                       show_frame_num();
+               out += sprintf(out, "- Frame %d\n", i); \
+               if (td->dma_handle != (dma_addr_t)uhci->frame[i])
                        out += sprintf(out, "    frame list does not match td->dma_handle!\n");
-               }
-               show_frame_num();
 
                head = &td->fl_list;
                tmp = head;
@@ -467,14 +348,11 @@ static int uhci_sprint_schedule(struct uhci_hcd *uhci, char *buf, int len)
        out += sprintf(out, "Skeleton QHs\n");
 
        for (i = 0; i < UHCI_NUM_SKELQH; ++i) {
-               int shown = 0;
+               int cnt = 0;
 
                qh = uhci->skelqh[i];
-
-               if (debug > 1) {
-                       show_qh_name();
-                       out += uhci_show_qh(qh, out, len - (out - buf), 4);
-               }
+               out += sprintf(out, "- %s\n", qh_names[i]); \
+               out += uhci_show_qh(qh, out, len - (out - buf), 4);
 
                /* Last QH is the Terminating QH, it's different */
                if (i == UHCI_NUM_SKELQH - 1) {
@@ -487,44 +365,27 @@ static int uhci_sprint_schedule(struct uhci_hcd *uhci, char *buf, int len)
                        continue;
                }
 
-               j = (i < 7) ? 7 : i+1;          /* Next skeleton */
-               if (list_empty(&qh->list)) {
-                       if (i < UHCI_NUM_SKELQH - 1) {
-                               if (qh->link !=
-                                   (cpu_to_le32(uhci->skelqh[j]->dma_handle) | UHCI_PTR_QH)) {
-                                       show_qh_name();
-                                       out += sprintf(out, "    skeleton QH not linked to next skeleton QH!\n");
-                               }
-                       }
-
-                       continue;
-               }
-
-               show_qh_name();
-
-               head = &qh->list;
+               j = (i < 9) ? 9 : i+1;          /* Next skeleton */
+               head = &qh->node;
                tmp = head->next;
 
                while (tmp != head) {
-                       qh = list_entry(tmp, struct uhci_qh, list);
-
+                       qh = list_entry(tmp, struct uhci_qh, node);
                        tmp = tmp->next;
-
-                       out += uhci_show_qh(qh, out, len - (out - buf), 4);
+                       if (++cnt <= 10)
+                               out += uhci_show_qh(qh, out,
+                                               len - (out - buf), 4);
                }
+               if ((cnt -= 10) > 0)
+                       out += sprintf(out, "    Skipped %d QHs\n", cnt);
 
-               if (i < UHCI_NUM_SKELQH - 1) {
+               if (i > 1 && i < UHCI_NUM_SKELQH - 1) {
                        if (qh->link !=
                            (cpu_to_le32(uhci->skelqh[j]->dma_handle) | UHCI_PTR_QH))
                                out += sprintf(out, "    last QH not linked to next skeleton!\n");
                }
        }
 
-       if (debug > 2)
-               out += uhci_show_lists(uhci, out, len - (out - buf));
-
-       spin_unlock_irqrestore(&uhci->lock, flags);
-
        return out - buf;
 }
 
@@ -541,6 +402,7 @@ static int uhci_debug_open(struct inode *inode, struct file *file)
        struct uhci_hcd *uhci = inode->u.generic_ip;
        struct uhci_debug *up;
        int ret = -ENOMEM;
+       unsigned long flags;
 
        lock_kernel();
        up = kmalloc(sizeof(*up), GFP_KERNEL);
@@ -553,7 +415,9 @@ static int uhci_debug_open(struct inode *inode, struct file *file)
                goto out;
        }
 
+       spin_lock_irqsave(&uhci->lock, flags);
        up->size = uhci_sprint_schedule(uhci, up->data, MAX_OUTPUT);
+       spin_unlock_irqrestore(&uhci->lock, flags);
 
        file->private_data = up;
 
index dfe121d..1ff4b88 100644 (file)
@@ -54,7 +54,7 @@
 /*
  * Version Information
  */
-#define DRIVER_VERSION "v2.3"
+#define DRIVER_VERSION "v3.0"
 #define DRIVER_AUTHOR "Linus 'Frodo Rabbit' Torvalds, Johannes Erdfelt, \
 Randy Dunlap, Georg Acher, Deti Fliegl, Thomas Sailer, Roman Weissgaerber, \
 Alan Stern"
@@ -489,15 +489,11 @@ static int uhci_start(struct usb_hcd *hcd)
        uhci->fsbrtimeout = 0;
 
        spin_lock_init(&uhci->lock);
-       INIT_LIST_HEAD(&uhci->qh_remove_list);
 
        INIT_LIST_HEAD(&uhci->td_remove_list);
-
-       INIT_LIST_HEAD(&uhci->urb_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);
 
@@ -540,7 +536,7 @@ static int uhci_start(struct usb_hcd *hcd)
        }
 
        for (i = 0; i < UHCI_NUM_SKELQH; i++) {
-               uhci->skelqh[i] = uhci_alloc_qh(uhci);
+               uhci->skelqh[i] = uhci_alloc_qh(uhci, NULL, NULL);
                if (!uhci->skelqh[i]) {
                        dev_err(uhci_dev(uhci), "unable to allocate QH\n");
                        goto err_alloc_skelqh;
@@ -557,13 +553,17 @@ static int uhci_start(struct usb_hcd *hcd)
                        uhci->skel_int16_qh->link =
                        uhci->skel_int8_qh->link =
                        uhci->skel_int4_qh->link =
-                       uhci->skel_int2_qh->link =
-                       cpu_to_le32(uhci->skel_int1_qh->dma_handle) | UHCI_PTR_QH;
-       uhci->skel_int1_qh->link = cpu_to_le32(uhci->skel_ls_control_qh->dma_handle) | UHCI_PTR_QH;
-
-       uhci->skel_ls_control_qh->link = cpu_to_le32(uhci->skel_fs_control_qh->dma_handle) | UHCI_PTR_QH;
-       uhci->skel_fs_control_qh->link = cpu_to_le32(uhci->skel_bulk_qh->dma_handle) | UHCI_PTR_QH;
-       uhci->skel_bulk_qh->link = cpu_to_le32(uhci->skel_term_qh->dma_handle) | UHCI_PTR_QH;
+                       uhci->skel_int2_qh->link = UHCI_PTR_QH |
+                       cpu_to_le32(uhci->skel_int1_qh->dma_handle);
+
+       uhci->skel_int1_qh->link = UHCI_PTR_QH |
+                       cpu_to_le32(uhci->skel_ls_control_qh->dma_handle);
+       uhci->skel_ls_control_qh->link = UHCI_PTR_QH |
+                       cpu_to_le32(uhci->skel_fs_control_qh->dma_handle);
+       uhci->skel_fs_control_qh->link = UHCI_PTR_QH |
+                       cpu_to_le32(uhci->skel_bulk_qh->dma_handle);
+       uhci->skel_bulk_qh->link = UHCI_PTR_QH |
+                       cpu_to_le32(uhci->skel_term_qh->dma_handle);
 
        /* This dummy TD is to work around a bug in Intel PIIX controllers */
        uhci_fill_td(uhci->term_td, 0, uhci_explen(0) |
@@ -589,15 +589,15 @@ static int uhci_start(struct usb_hcd *hcd)
 
                /*
                 * ffs (Find First bit Set) does exactly what we need:
-                * 1,3,5,...  => ffs = 0 => use skel_int2_qh = skelqh[6],
-                * 2,6,10,... => ffs = 1 => use skel_int4_qh = skelqh[5], etc.
-                * ffs > 6 => not on any high-period queue, so use
-                *      skel_int1_qh = skelqh[7].
+                * 1,3,5,...  => ffs = 0 => use skel_int2_qh = skelqh[8],
+                * 2,6,10,... => ffs = 1 => use skel_int4_qh = skelqh[7], etc.
+                * ffs >= 7 => not on any high-period queue, so use
+                *      skel_int1_qh = skelqh[9].
                 * Add UHCI_NUMFRAMES to insure at least one bit is set.
                 */
-               irq = 6 - (int) __ffs(i + UHCI_NUMFRAMES);
-               if (irq < 0)
-                       irq = 7;
+               irq = 8 - (int) __ffs(i + UHCI_NUMFRAMES);
+               if (irq <= 1)
+                       irq = 9;
 
                /* Only place we don't use the frame list routines */
                uhci->frame[i] = UHCI_PTR_QH |
@@ -767,13 +767,30 @@ static int uhci_resume(struct usb_hcd *hcd)
 }
 #endif
 
-/* Wait until all the URBs for a particular device/endpoint are gone */
+/* Wait until a particular device/endpoint's QH is idle, and free it */
 static void uhci_hcd_endpoint_disable(struct usb_hcd *hcd,
-               struct usb_host_endpoint *ep)
+               struct usb_host_endpoint *hep)
 {
        struct uhci_hcd *uhci = hcd_to_uhci(hcd);
+       struct uhci_qh *qh;
+
+       spin_lock_irq(&uhci->lock);
+       qh = (struct uhci_qh *) hep->hcpriv;
+       if (qh == NULL)
+               goto done;
 
-       wait_event_interruptible(uhci->waitqh, list_empty(&ep->urb_list));
+       while (qh->state != QH_STATE_IDLE) {
+               ++uhci->num_waiting;
+               spin_unlock_irq(&uhci->lock);
+               wait_event_interruptible(uhci->waitqh,
+                               qh->state == QH_STATE_IDLE);
+               spin_lock_irq(&uhci->lock);
+               --uhci->num_waiting;
+       }
+
+       uhci_free_qh(uhci, qh);
+done:
+       spin_unlock_irq(&uhci->lock);
 }
 
 static int uhci_hcd_get_frame_number(struct usb_hcd *hcd)
index 8b4b887..7a9481c 100644 (file)
@@ -28,8 +28,9 @@
 #define   USBSTS_USBINT                0x0001  /* Interrupt due to IOC */
 #define   USBSTS_ERROR         0x0002  /* Interrupt due to error */
 #define   USBSTS_RD            0x0004  /* Resume Detect */
-#define   USBSTS_HSE           0x0008  /* Host System Error - basically PCI problems */
-#define   USBSTS_HCPE          0x0010  /* Host Controller Process Error - the scripts were buggy */
+#define   USBSTS_HSE           0x0008  /* Host System Error: PCI problems */
+#define   USBSTS_HCPE          0x0010  /* Host Controller Process Error:
+                                        * the schedule is buggy */
 #define   USBSTS_HCH           0x0020  /* HC Halted */
 
 /* Interrupt enable register */
@@ -47,7 +48,8 @@
 /* USB port status and control registers */
 #define USBPORTSC1     16
 #define USBPORTSC2     18
-#define   USBPORTSC_CCS                0x0001  /* Current Connect Status ("device present") */
+#define   USBPORTSC_CCS                0x0001  /* Current Connect Status
+                                        * ("device present") */
 #define   USBPORTSC_CSC                0x0002  /* Connect Status Change */
 #define   USBPORTSC_PE         0x0004  /* Port Enable */
 #define   USBPORTSC_PEC                0x0008  /* Port Enable Change */
 #define   USBLEGSUP_RWC                0x8f00  /* the R/WC bits */
 #define   USBLEGSUP_RO         0x5040  /* R/O and reserved bits */
 
-#define UHCI_PTR_BITS          cpu_to_le32(0x000F)
-#define UHCI_PTR_TERM          cpu_to_le32(0x0001)
-#define UHCI_PTR_QH            cpu_to_le32(0x0002)
-#define UHCI_PTR_DEPTH         cpu_to_le32(0x0004)
-#define UHCI_PTR_BREADTH       cpu_to_le32(0x0000)
+#define UHCI_PTR_BITS          __constant_cpu_to_le32(0x000F)
+#define UHCI_PTR_TERM          __constant_cpu_to_le32(0x0001)
+#define UHCI_PTR_QH            __constant_cpu_to_le32(0x0002)
+#define UHCI_PTR_DEPTH         __constant_cpu_to_le32(0x0004)
+#define UHCI_PTR_BREADTH       __constant_cpu_to_le32(0x0000)
 
 #define UHCI_NUMFRAMES         1024    /* in the frame list [array] */
 #define UHCI_MAX_SOF_NUMBER    2047    /* in an SOF packet */
-#define CAN_SCHEDULE_FRAMES    1000    /* how far future frames can be scheduled */
+#define CAN_SCHEDULE_FRAMES    1000    /* how far in the future frames
+                                        * can be scheduled */
 
 
 /*
  */
 
 /*
- * One role of a QH is to hold a queue of TDs for some endpoint.  Each QH is
- * used with one URB, and qh->element (updated by the HC) is either:
- *   - the next unprocessed TD for the URB, or
- *   - UHCI_PTR_TERM (when there's no more traffic for this endpoint), or
- *   - the QH for the next URB queued to the same endpoint.
+ * One role of a QH is to hold a queue of TDs for some endpoint.  One QH goes
+ * with each endpoint, and qh->element (updated by the HC) is either:
+ *   - the next unprocessed TD in the endpoint's queue, or
+ *   - UHCI_PTR_TERM (when there's no more traffic for this endpoint).
  *
  * The other role of a QH is to serve as a "skeleton" framelist entry, so we
  * can easily splice a QH for some endpoint into the schedule at the right
  * place.  Then qh->element is UHCI_PTR_TERM.
  *
- * In the frame list, qh->link maintains a list of QHs seen by the HC:
+ * In the schedule, qh->link maintains a list of QHs seen by the HC:
  *     skel1 --> ep1-qh --> ep2-qh --> ... --> skel2 --> ...
+ *
+ * qh->node is the software equivalent of qh->link.  The differences
+ * are that the software list is doubly-linked and QHs in the UNLINKING
+ * state are on the software list but not the hardware schedule.
+ *
+ * For bookkeeping purposes we maintain QHs even for Isochronous endpoints,
+ * but they never get added to the hardware schedule.
  */
+#define QH_STATE_IDLE          1       /* QH is not being used */
+#define QH_STATE_UNLINKING     2       /* QH has been removed from the
+                                        * schedule but the hardware may
+                                        * still be using it */
+#define QH_STATE_ACTIVE                3       /* QH is on the schedule */
+
 struct uhci_qh {
        /* Hardware fields */
-       __le32 link;                    /* Next queue */
-       __le32 element;                 /* Queue element pointer */
+       __le32 link;                    /* Next QH in the schedule */
+       __le32 element;                 /* Queue element (TD) pointer */
 
        /* Software fields */
        dma_addr_t dma_handle;
 
-       struct urb_priv *urbp;
+       struct list_head node;          /* Node in the list of QHs */
+       struct usb_host_endpoint *hep;  /* Endpoint information */
+       struct usb_device *udev;
+       struct list_head queue;         /* Queue of urbps for this QH */
+       struct uhci_qh *skel;           /* Skeleton for this QH */
 
-       struct list_head list;
-       struct list_head remove_list;
+       unsigned int unlink_frame;      /* When the QH was unlinked */
+       int state;                      /* QH_STATE_xxx; see above */
 } __attribute__((aligned(16)));
 
 /*
  * We need a special accessor for the element pointer because it is
  * subject to asynchronous updates by the controller.
  */
-static __le32 inline qh_element(struct uhci_qh *qh) {
+static inline __le32 qh_element(struct uhci_qh *qh) {
        __le32 element = qh->element;
 
        barrier();
@@ -149,11 +168,13 @@ static __le32 inline qh_element(struct uhci_qh *qh) {
 #define TD_CTRL_ACTLEN_MASK    0x7FF   /* actual length, encoded as n - 1 */
 
 #define TD_CTRL_ANY_ERROR      (TD_CTRL_STALLED | TD_CTRL_DBUFERR | \
-                                TD_CTRL_BABBLE | TD_CTRL_CRCTIME | TD_CTRL_BITSTUFF)
+                                TD_CTRL_BABBLE | TD_CTRL_CRCTIME | \
+                                TD_CTRL_BITSTUFF)
 
 #define uhci_maxerr(err)               ((err) << TD_CTRL_C_ERR_SHIFT)
 #define uhci_status_bits(ctrl_sts)     ((ctrl_sts) & 0xF60000)
-#define uhci_actual_length(ctrl_sts)   (((ctrl_sts) + 1) & TD_CTRL_ACTLEN_MASK) /* 1-based */
+#define uhci_actual_length(ctrl_sts)   (((ctrl_sts) + 1) & \
+                       TD_CTRL_ACTLEN_MASK)    /* 1-based */
 
 /*
  * for TD <info>: (a.k.a. Token)
@@ -163,7 +184,7 @@ static __le32 inline qh_element(struct uhci_qh *qh) {
 #define TD_TOKEN_TOGGLE_SHIFT  19
 #define TD_TOKEN_TOGGLE                (1 << 19)
 #define TD_TOKEN_EXPLEN_SHIFT  21
-#define TD_TOKEN_EXPLEN_MASK   0x7FF           /* expected length, encoded as n - 1 */
+#define TD_TOKEN_EXPLEN_MASK   0x7FF   /* expected length, encoded as n-1 */
 #define TD_TOKEN_PID_MASK      0xFF
 
 #define uhci_explen(len)       ((((len) - 1) & TD_TOKEN_EXPLEN_MASK) << \
@@ -187,7 +208,7 @@ static __le32 inline qh_element(struct uhci_qh *qh) {
  * sw space after the TD entry.
  *
  * td->link points to either another TD (not necessarily for the same urb or
- * even the same endpoint), or nothing (PTR_TERM), or a QH (for queued urbs).
+ * even the same endpoint), or nothing (PTR_TERM), or a QH.
  */
 struct uhci_td {
        /* Hardware fields */
@@ -210,7 +231,7 @@ struct uhci_td {
  * We need a special accessor for the control/status word because it is
  * subject to asynchronous updates by the controller.
  */
-static u32 inline td_status(struct uhci_td *td) {
+static inline u32 td_status(struct uhci_td *td) {
        __le32 status = td->status;
 
        barrier();
@@ -223,17 +244,14 @@ static u32 inline td_status(struct uhci_td *td) {
  */
 
 /*
- * The UHCI driver places Interrupt, Control and Bulk into QHs both
- * to group together TDs for one transfer, and also to facilitate queuing
- * of URBs. To make it easy to insert entries into the schedule, we have
- * a skeleton of QHs for each predefined Interrupt latency, low-speed
- * control, full-speed control and terminating QH (see explanation for
- * the terminating QH below).
+ * The UHCI driver uses QHs with Interrupt, Control and Bulk URBs for
+ * automatic queuing. To make it easy to insert entries into the schedule,
+ * we have a skeleton of QHs for each predefined Interrupt latency,
+ * low-speed control, full-speed control, bulk, and terminating QH
+ * (see explanation for the terminating QH below).
  *
  * When we want to add a new QH, we add it to the end of the list for the
- * skeleton QH.
- *
- * For instance, the queue can look like this:
+ * skeleton QH.  For instance, the schedule list can look like this:
  *
  * skel int128 QH
  * dev 1 interrupt QH
@@ -256,26 +274,31 @@ static u32 inline td_status(struct uhci_td *td) {
  * - To loop back to the full-speed control queue for full-speed bandwidth
  *   reclamation.
  *
- * Isochronous transfers are stored before the start of the skeleton
- * schedule and don't use QHs. While the UHCI spec doesn't forbid the
- * use of QHs for Isochronous, it doesn't use them either. And the spec
- * says that queues never advance on an error completion status, which
- * makes them totally unsuitable for Isochronous transfers.
+ * There's a special skeleton QH for Isochronous QHs.  It never appears
+ * on the schedule, and Isochronous TDs go on the schedule before the
+ * the skeleton QHs.  The hardware accesses them directly rather than
+ * through their QH, which is used only for bookkeeping purposes.
+ * While the UHCI spec doesn't forbid the use of QHs for Isochronous,
+ * it doesn't use them either.  And the spec says that queues never
+ * advance on an error completion status, which makes them totally
+ * unsuitable for Isochronous transfers.
  */
 
-#define UHCI_NUM_SKELQH                12
-#define skel_int128_qh         skelqh[0]
-#define skel_int64_qh          skelqh[1]
-#define skel_int32_qh          skelqh[2]
-#define skel_int16_qh          skelqh[3]
-#define skel_int8_qh           skelqh[4]
-#define skel_int4_qh           skelqh[5]
-#define skel_int2_qh           skelqh[6]
-#define skel_int1_qh           skelqh[7]
-#define skel_ls_control_qh     skelqh[8]
-#define skel_fs_control_qh     skelqh[9]
-#define skel_bulk_qh           skelqh[10]
-#define skel_term_qh           skelqh[11]
+#define UHCI_NUM_SKELQH                14
+#define skel_unlink_qh         skelqh[0]
+#define skel_iso_qh            skelqh[1]
+#define skel_int128_qh         skelqh[2]
+#define skel_int64_qh          skelqh[3]
+#define skel_int32_qh          skelqh[4]
+#define skel_int16_qh          skelqh[5]
+#define skel_int8_qh           skelqh[6]
+#define skel_int4_qh           skelqh[7]
+#define skel_int2_qh           skelqh[8]
+#define skel_int1_qh           skelqh[9]
+#define skel_ls_control_qh     skelqh[10]
+#define skel_fs_control_qh     skelqh[11]
+#define skel_bulk_qh           skelqh[12]
+#define skel_term_qh           skelqh[13]
 
 /*
  * Search tree for determining where <interval> fits in the skelqh[]
@@ -293,21 +316,21 @@ static inline int __interval_to_skel(int interval)
        if (interval < 16) {
                if (interval < 4) {
                        if (interval < 2)
-                               return 7;       /* int1 for 0-1 ms */
-                       return 6;               /* int2 for 2-3 ms */
+                               return 9;       /* int1 for 0-1 ms */
+                       return 8;               /* int2 for 2-3 ms */
                }
                if (interval < 8)
-                       return 5;               /* int4 for 4-7 ms */
-               return 4;                       /* int8 for 8-15 ms */
+                       return 7;               /* int4 for 4-7 ms */
+               return 6;                       /* int8 for 8-15 ms */
        }
        if (interval < 64) {
                if (interval < 32)
-                       return 3;               /* int16 for 16-31 ms */
-               return 2;                       /* int32 for 32-63 ms */
+                       return 5;               /* int16 for 16-31 ms */
+               return 4;                       /* int32 for 32-63 ms */
        }
        if (interval < 128)
-               return 1;                       /* int64 for 64-127 ms */
-       return 0;                               /* int128 for 128-255 ms (Max.) */
+               return 3;                       /* int64 for 64-127 ms */
+       return 2;                               /* int128 for 128-255 ms (Max.) */
 }
 
 
@@ -363,12 +386,12 @@ struct uhci_hcd {
 
        spinlock_t lock;
 
-       dma_addr_t frame_dma_handle;            /* Hardware frame list */
+       dma_addr_t frame_dma_handle;    /* Hardware frame list */
        __le32 *frame;
-       void **frame_cpu;                       /* CPU's frame list */
+       void **frame_cpu;               /* CPU's frame list */
 
-       int fsbr;                               /* Full-speed bandwidth reclamation */
-       unsigned long fsbrtimeout;              /* FSBR delay */
+       int fsbr;                       /* Full-speed bandwidth reclamation */
+       unsigned long fsbrtimeout;      /* FSBR delay */
 
        enum uhci_rh_state rh_state;
        unsigned long auto_stop_time;           /* When to AUTO_STOP */
@@ -392,24 +415,19 @@ struct uhci_hcd {
        /* Main list of URBs currently controlled by this HC */
        struct list_head urb_list;
 
-       /* List of QHs that are done, but waiting to be unlinked (race) */
-       struct list_head qh_remove_list;
-       unsigned int qh_remove_age;             /* Age in frames */
-
        /* 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 asynchronously unlinked URBs */
-       struct list_head urb_remove_list;
-       unsigned int urb_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 */
 
        wait_queue_head_t waitqh;               /* endpoint_disable waiters */
+       int num_waiting;                        /* Number of waiters */
 };
 
 /* Convert between a usb_hcd pointer and the corresponding uhci_hcd */
@@ -430,22 +448,19 @@ static inline struct usb_hcd *uhci_to_hcd(struct uhci_hcd *uhci)
  */
 struct urb_priv {
        struct list_head urb_list;
+       struct list_head node;          /* Node in the QH's urbp list */
 
        struct urb *urb;
 
        struct uhci_qh *qh;             /* QH for this URB */
        struct list_head td_list;
 
-       unsigned fsbr : 1;              /* URB turned on FSBR */
-       unsigned fsbr_timeout : 1;      /* URB timed out on FSBR */
-       unsigned queued : 1;            /* QH was queued (not linked in) */
-       unsigned short_control_packet : 1;      /* If we get a short packet during */
-                                               /*  a control transfer, retrigger */
-                                               /*  the status phase */
-
        unsigned long fsbrtime;         /* In jiffies */
 
-       struct list_head queue_list;
+       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 7823980..b1b551a 100644 (file)
  * (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)