This patch (as931), adapted from a patch by Olav Kongas, makes a small
set of conservative changes to the isp116x-hcd driver in preparation
for the removal of urb->status.

        finish_request() is moved up in the source and is called
        as soon as the URB is known to have completed, rather than
        after all the active endpoints have been scanned.

        Control URBs that fail because of an underrun with
        URB_SHORT_NOT_OK set will complete immediately, with no
        status stage.  This is consistent with the behavior of
        other host controller drivers.

        The status of a completed URB is kept in a local variable
        and copied to urb->status only when the URB is about to be
        given back.

        Some unnecessary uses of urb->lock are removed.

Signed-off-by: Alan Stern <[EMAIL PROTECTED]>

---

Index: usb-2.6/drivers/usb/host/isp116x-hcd.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/isp116x-hcd.c
+++ usb-2.6/drivers/usb/host/isp116x-hcd.c
@@ -228,7 +228,6 @@ static void preproc_atl_queue(struct isp
                                   struct urb, urb_list);
                ptd = &ep->ptd;
                len = ep->length;
-               spin_lock(&urb->lock);
                ep->data = (unsigned char *)urb->transfer_buffer
                    + urb->actual_length;
 
@@ -264,7 +263,6 @@ static void preproc_atl_queue(struct isp
                    | PTD_EP(ep->epnum);
                ptd->len = PTD_LEN(len) | PTD_DIR(dir);
                ptd->faddr = PTD_FA(usb_pipedevice(urb->pipe));
-               spin_unlock(&urb->lock);
                if (!ep->active) {
                        ptd->mps |= PTD_LAST_MSK;
                        isp116x->atl_last_dir = dir;
@@ -275,6 +273,61 @@ static void preproc_atl_queue(struct isp
 }
 
 /*
+  Take done or failed requests out of schedule. Give back
+  processed urbs.
+*/
+static void finish_request(struct isp116x *isp116x, struct isp116x_ep *ep,
+                          struct urb *urb)
+__releases(isp116x->lock) __acquires(isp116x->lock)
+{
+       unsigned i;
+
+       urb->hcpriv = NULL;
+       ep->error_count = 0;
+
+       if (usb_pipecontrol(urb->pipe))
+               ep->nextpid = USB_PID_SETUP;
+
+       urb_dbg(urb, "Finish");
+
+       spin_unlock(&isp116x->lock);
+       usb_hcd_giveback_urb(isp116x_to_hcd(isp116x), urb);
+       spin_lock(&isp116x->lock);
+
+       /* take idle endpoints out of the schedule */
+       if (!list_empty(&ep->hep->urb_list))
+               return;
+
+       /* async deschedule */
+       if (!list_empty(&ep->schedule)) {
+               list_del_init(&ep->schedule);
+               return;
+       }
+
+       /* periodic deschedule */
+       DBG("deschedule qh%d/%p branch %d\n", ep->period, ep, ep->branch);
+       for (i = ep->branch; i < PERIODIC_SIZE; i += ep->period) {
+               struct isp116x_ep *temp;
+               struct isp116x_ep **prev = &isp116x->periodic[i];
+
+               while (*prev && ((temp = *prev) != ep))
+                       prev = &temp->next;
+               if (*prev)
+                       *prev = ep->next;
+               isp116x->load[i] -= ep->load;
+       }
+       ep->branch = PERIODIC_SIZE;
+       isp116x_to_hcd(isp116x)->self.bandwidth_allocated -=
+           ep->load / ep->period;
+
+       /* switch irq type? */
+       if (!--isp116x->periodic_count) {
+               isp116x->irqenb &= ~HCuPINT_SOF;
+               isp116x->irqenb |= HCuPINT_ATL;
+       }
+}
+
+/*
   Analyze transfer results, handle partial transfers and errors
 */
 static void postproc_atl_queue(struct isp116x *isp116x)
@@ -284,6 +337,7 @@ static void postproc_atl_queue(struct is
        struct usb_device *udev;
        struct ptd *ptd;
        int short_not_ok;
+       int status;
        u8 cc;
 
        for (ep = isp116x->atl_active; ep; ep = ep->active) {
@@ -294,55 +348,38 @@ static void postproc_atl_queue(struct is
                ptd = &ep->ptd;
                cc = PTD_GET_CC(ptd);
                short_not_ok = 1;
-               spin_lock(&urb->lock);
+               status = -EINPROGRESS;
 
-               /* Data underrun is special. For allowed underrun
-                  we clear the error and continue as normal. For
-                  forbidden underrun we finish the DATA stage
-                  immediately while for control transfer,
-                  we do a STATUS stage. */
                if (cc == TD_DATAUNDERRUN) {
                        if (!(urb->transfer_flags & URB_SHORT_NOT_OK)) {
                                DBG("Allowed data underrun\n");
                                cc = TD_CC_NOERROR;
                                short_not_ok = 0;
                        } else {
-                               ep->error_count = 1;
-                               if (usb_pipecontrol(urb->pipe))
-                                       ep->nextpid = USB_PID_ACK;
-                               else
-                                       usb_settoggle(udev, ep->epnum,
-                                                     ep->nextpid ==
-                                                     USB_PID_OUT,
-                                                     PTD_GET_TOGGLE(ptd));
+                               usb_settoggle(udev, ep->epnum,
+                                             ep->nextpid ==
+                                             USB_PID_OUT,
+                                             PTD_GET_TOGGLE(ptd));
                                urb->actual_length += PTD_GET_COUNT(ptd);
-                               urb->status = cc_to_error[TD_DATAUNDERRUN];
-                               spin_unlock(&urb->lock);
-                               continue;
+                               status = cc_to_error[TD_DATAUNDERRUN];
+                               goto done;
                        }
                }
-               /* Keep underrun error through the STATUS stage */
-               if (urb->status == cc_to_error[TD_DATAUNDERRUN])
-                       cc = TD_DATAUNDERRUN;
 
                if (cc != TD_CC_NOERROR && cc != TD_NOTACCESSED
                    && (++ep->error_count >= 3 || cc == TD_CC_STALL
                        || cc == TD_DATAOVERRUN)) {
-                       if (urb->status == -EINPROGRESS)
-                               urb->status = cc_to_error[cc];
+                       status = cc_to_error[cc];
                        if (ep->nextpid == USB_PID_ACK)
                                ep->nextpid = 0;
-                       spin_unlock(&urb->lock);
-                       continue;
+                       goto done;
                }
                /* According to usb spec, zero-length Int transfer signals
                   finishing of the urb. Hey, does this apply only
                   for IN endpoints? */
                if (usb_pipeint(urb->pipe) && !PTD_GET_LEN(ptd)) {
-                       if (urb->status == -EINPROGRESS)
-                               urb->status = 0;
-                       spin_unlock(&urb->lock);
-                       continue;
+                       status = 0;
+                       goto done;
                }
 
                /* Relax after previously failed, but later succeeded
@@ -381,8 +418,8 @@ static void postproc_atl_queue(struct is
                        /* All data for this URB is transferred, let's finish */
                        if (usb_pipecontrol(urb->pipe))
                                ep->nextpid = USB_PID_ACK;
-                       else if (urb->status == -EINPROGRESS)
-                               urb->status = 0;
+                       else
+                               status = 0;
                        break;
                case USB_PID_SETUP:
                        if (PTD_GET_ACTIVE(ptd)
@@ -402,69 +439,22 @@ static void postproc_atl_queue(struct is
                        if (PTD_GET_ACTIVE(ptd)
                            || (cc != TD_CC_NOERROR && cc < 0x0E))
                                break;
-                       if (urb->status == -EINPROGRESS)
-                               urb->status = 0;
+                       status = 0;
                        ep->nextpid = 0;
                        break;
                default:
                        BUG();
                }
-               spin_unlock(&urb->lock);
-       }
-}
-
-/*
-  Take done or failed requests out of schedule. Give back
-  processed urbs.
-*/
-static void finish_request(struct isp116x *isp116x, struct isp116x_ep *ep,
-                          struct urb *urb)
-__releases(isp116x->lock) __acquires(isp116x->lock)
-{
-       unsigned i;
-
-       urb->hcpriv = NULL;
-       ep->error_count = 0;
-
-       if (usb_pipecontrol(urb->pipe))
-               ep->nextpid = USB_PID_SETUP;
-
-       urb_dbg(urb, "Finish");
-
-       spin_unlock(&isp116x->lock);
-       usb_hcd_giveback_urb(isp116x_to_hcd(isp116x), urb);
-       spin_lock(&isp116x->lock);
-
-       /* take idle endpoints out of the schedule */
-       if (!list_empty(&ep->hep->urb_list))
-               return;
-
-       /* async deschedule */
-       if (!list_empty(&ep->schedule)) {
-               list_del_init(&ep->schedule);
-               return;
-       }
 
-       /* periodic deschedule */
-       DBG("deschedule qh%d/%p branch %d\n", ep->period, ep, ep->branch);
-       for (i = ep->branch; i < PERIODIC_SIZE; i += ep->period) {
-               struct isp116x_ep *temp;
-               struct isp116x_ep **prev = &isp116x->periodic[i];
-
-               while (*prev && ((temp = *prev) != ep))
-                       prev = &temp->next;
-               if (*prev)
-                       *prev = ep->next;
-               isp116x->load[i] -= ep->load;
-       }
-       ep->branch = PERIODIC_SIZE;
-       isp116x_to_hcd(isp116x)->self.bandwidth_allocated -=
-           ep->load / ep->period;
-
-       /* switch irq type? */
-       if (!--isp116x->periodic_count) {
-               isp116x->irqenb &= ~HCuPINT_SOF;
-               isp116x->irqenb |= HCuPINT_ATL;
+ done:
+               if (status != -EINPROGRESS) {
+                       spin_lock(&urb->lock);
+                       if (urb->status == -EINPROGRESS)
+                               urb->status = status;
+                       spin_unlock(&urb->lock);
+               }
+               if (urb->status != -EINPROGRESS)
+                       finish_request(isp116x, ep, urb);
        }
 }
 
@@ -570,9 +560,6 @@ static void start_atl_transfers(struct i
 */
 static void finish_atl_transfers(struct isp116x *isp116x)
 {
-       struct isp116x_ep *ep;
-       struct urb *urb;
-
        if (!isp116x->atl_active)
                return;
        /* Fifo not ready? */
@@ -582,16 +569,6 @@ static void finish_atl_transfers(struct 
        atomic_inc(&isp116x->atl_finishing);
        unpack_fifo(isp116x);
        postproc_atl_queue(isp116x);
-       for (ep = isp116x->atl_active; ep; ep = ep->active) {
-               urb =
-                   container_of(ep->hep->urb_list.next, struct urb, urb_list);
-               /* USB_PID_ACK check here avoids finishing of
-                  control transfers, for which TD_DATAUNDERRUN
-                  occured, while URB_SHORT_NOT_OK was set */
-               if (urb && urb->status != -EINPROGRESS
-                   && ep->nextpid != USB_PID_ACK)
-                       finish_request(isp116x, ep, urb);
-       }
        atomic_dec(&isp116x->atl_finishing);
 }
 
@@ -821,15 +798,12 @@ static int isp116x_urb_enqueue(struct us
        }
 
        /* in case of unlink-during-submit */
-       spin_lock(&urb->lock);
        if (urb->status != -EINPROGRESS) {
-               spin_unlock(&urb->lock);
                finish_request(isp116x, ep, urb);
                ret = 0;
                goto fail;
        }
        urb->hcpriv = hep;
-       spin_unlock(&urb->lock);
        start_atl_transfers(isp116x);
 
       fail:


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