USB: reorganize urb->status use in ohci-hcd

This patch (as975) reorganizes the way ohci-hcd sets urb->status.  It
now keeps the information in a local variable until the last moment.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 17 insertions, 21 deletions

diff --git a/drivers/usb/host/ohci-q.c b/drivers/usb/host/ohci-q.c
index 860e55ff67a1..13d31edd1a86 100644
--- a/drivers/usb/host/ohci-q.c
+++ b/drivers/usb/host/ohci-q.c
@@ -36,18 +36,15 @@ static void urb_free_priv (struct ohci_hcd *hc, urb_priv_t *urb_priv)
  * PRECONDITION:  ohci lock held, irqs blocked.
  */
 static void
-finish_urb (struct ohci_hcd *ohci, struct urb *urb)
+finish_urb(struct ohci_hcd *ohci, struct urb *urb, int status)
 __releases(ohci->lock)
 __acquires(ohci->lock)
 {
         // ASSERT (urb->hcpriv != 0);
 
         urb_free_priv (ohci, urb->hcpriv);
-
-        spin_lock (&urb->lock);
-        if (likely (urb->status == -EINPROGRESS))
-                urb->status = 0;
-        spin_unlock (&urb->lock);
+        if (likely(status == -EINPROGRESS))
+                status = 0;
 
         switch (usb_pipetype (urb->pipe)) {
         case PIPE_ISOCHRONOUS:
@@ -59,12 +56,13 @@ __acquires(ohci->lock)
         }
 
 #ifdef OHCI_VERBOSE_DEBUG
-        urb_print (urb, "RET", usb_pipeout (urb->pipe));
+        urb_print(urb, "RET", usb_pipeout (urb->pipe), status);
 #endif
 
         /* urb->complete() can reenter this HCD */
         usb_hcd_unlink_urb_from_ep(ohci_to_hcd(ohci), urb);
         spin_unlock (&ohci->lock);
+        urb->status = status;
         usb_hcd_giveback_urb (ohci_to_hcd(ohci), urb);
         spin_lock (&ohci->lock);
 
@@ -702,19 +700,18 @@ static void td_submit_urb (
  * Done List handling functions
  *-------------------------------------------------------------------------*/
 
-/* calculate transfer length/status and update the urb
- * PRECONDITION:  irqsafe (only for urb->status locking)
- */
-static void td_done (struct ohci_hcd *ohci, struct urb *urb, struct td *td)
+/* calculate transfer length/status and update the urb */
+static int td_done(struct ohci_hcd *ohci, struct urb *urb, struct td *td)
 {
         u32     tdINFO = hc32_to_cpup (ohci, &td->hwINFO);
         int     cc = 0;
+        int     status = -EINPROGRESS;
 
         list_del (&td->td_list);
 
         /* ISO ... drivers see per-TD length/status */
         if (tdINFO & TD_ISO) {
-                u16     tdPSW = ohci_hwPSW (ohci, td, 0);
+                u16     tdPSW = ohci_hwPSW(ohci, td, 0);
                 int     dlen = 0;
 
                 /* NOTE:  assumes FC in tdINFO == 0, and that
@@ -723,7 +720,7 @@ static void td_done (struct ohci_hcd *ohci, struct urb *urb, struct td *td)
 
                 cc = (tdPSW >> 12) & 0xF;
                 if (tdINFO & TD_CC)     /* hc didn't touch? */
-                        return;
+                        return status;
 
                 if (usb_pipeout (urb->pipe))
                         dlen = urb->iso_frame_desc [td->index].length;
@@ -756,11 +753,8 @@ static void td_done (struct ohci_hcd *ohci, struct urb *urb, struct td *td)
                 if (cc == TD_DATAUNDERRUN
                                 && !(urb->transfer_flags & URB_SHORT_NOT_OK))
                         cc = TD_CC_NOERROR;
-                if (cc != TD_CC_NOERROR && cc < 0x0E) {
-                        spin_lock (&urb->lock);
-                        urb->status = cc_to_error[cc];
-                        spin_unlock (&urb->lock);
-                }
+                if (cc != TD_CC_NOERROR && cc < 0x0E)
+                        status = cc_to_error[cc];
 
                 /* count all non-empty packets except control SETUP packet */
                 if ((type != PIPE_CONTROL || td->index != 0) && tdBE != 0) {
@@ -779,6 +773,7 @@ static void td_done (struct ohci_hcd *ohci, struct urb *urb, struct td *td)
                                 urb->actual_length,
                                 urb->transfer_buffer_length);
         }
+        return status;
 }
 
 /*-------------------------------------------------------------------------*/
@@ -979,7 +974,7 @@ rescan_this:
                         /* if URB is done, clean up */
                         if (urb_priv->td_cnt == urb_priv->length) {
                                 modified = completed = 1;
-                                finish_urb (ohci, urb);
+                                finish_urb(ohci, urb, 0);
                         }
                 }
                 if (completed && !list_empty (&ed->td_list))
@@ -1062,14 +1057,15 @@ static void takeback_td(struct ohci_hcd *ohci, struct td *td)
         struct urb      *urb = td->urb;
         urb_priv_t      *urb_priv = urb->hcpriv;
         struct ed       *ed = td->ed;
+        int             status;
 
         /* update URB's length and status from TD */
-        td_done(ohci, urb, td);
+        status = td_done(ohci, urb, td);
         urb_priv->td_cnt++;
 
         /* If all this urb's TDs are done, call complete() */
         if (urb_priv->td_cnt == urb_priv->length)
-                finish_urb(ohci, urb);
+                finish_urb(ohci, urb, status);
 
         /* clean schedule:  unlink EDs that are no longer busy */
         if (list_empty(&ed->td_list)) {