USB: Eliminate urb->status usage!

This patch (as979) removes the last vestiges of urb->status from the
host controller drivers and the root-hub emulator.  Now the field
doesn't get set until just before the URB's completion routine is
called.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
CC: Olav Kongas <ok@artecdesign.ee>
CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
CC: Tony Olech <tony.olech@elandigitalsystems.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 13 insertions, 12 deletions

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 4ac021e42cd8..1c5e5d35e08d 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -532,7 +532,6 @@ error:
 
         /* any errors get returned through the urb completion */
         spin_lock_irq(&hcd_root_hub_lock);
-        urb->status = status;
         usb_hcd_unlink_urb_from_ep(hcd, urb);
 
         /* This peculiar use of spinlocks echoes what real HC drivers do.
@@ -540,7 +539,7 @@ error:
          * RT-friendly.
          */
         spin_unlock(&hcd_root_hub_lock);
-        usb_hcd_giveback_urb(hcd, urb);
+        usb_hcd_giveback_urb(hcd, urb, status);
         spin_lock(&hcd_root_hub_lock);
 
         spin_unlock_irq(&hcd_root_hub_lock);
@@ -578,13 +577,12 @@ void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
                 if (urb) {
                         hcd->poll_pending = 0;
                         hcd->status_urb = NULL;
-                        urb->status = 0;
                         urb->actual_length = length;
                         memcpy(urb->transfer_buffer, buffer, length);
 
                         usb_hcd_unlink_urb_from_ep(hcd, urb);
                         spin_unlock(&hcd_root_hub_lock);
-                        usb_hcd_giveback_urb(hcd, urb);
+                        usb_hcd_giveback_urb(hcd, urb, 0);
                         spin_lock(&hcd_root_hub_lock);
                 } else {
                         length = 0;
@@ -677,7 +675,7 @@ static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
                         usb_hcd_unlink_urb_from_ep(hcd, urb);
 
                         spin_unlock(&hcd_root_hub_lock);
-                        usb_hcd_giveback_urb(hcd, urb);
+                        usb_hcd_giveback_urb(hcd, urb, status);
                         spin_lock(&hcd_root_hub_lock);
                 }
         }
@@ -1252,6 +1250,7 @@ int usb_hcd_unlink_urb (struct urb *urb, int status)
  * usb_hcd_giveback_urb - return URB from HCD to device driver
  * @hcd: host controller returning the URB
  * @urb: urb being returned to the USB device driver.
+ * @status: completion status code for the URB.
  * Context: in_interrupt()
  *
  * This hands the URB from HCD to its USB device driver, using its
@@ -1260,25 +1259,26 @@ int usb_hcd_unlink_urb (struct urb *urb, int status)
  * the device driver won't cause problems if it frees, modifies,
  * or resubmits this URB.
  *
- * If @urb was unlinked, the value of @urb->status will be overridden by
+ * If @urb was unlinked, the value of @status will be overridden by
  * @urb->unlinked.  Erroneous short transfers are detected in case
  * the HCD hasn't checked for them.
  */
-void usb_hcd_giveback_urb (struct usb_hcd *hcd, struct urb *urb)
+void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
 {
         urb->hcpriv = NULL;
         if (unlikely(urb->unlinked))
-                urb->status = urb->unlinked;
+                status = urb->unlinked;
         else if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
                         urb->actual_length < urb->transfer_buffer_length &&
-                        !urb->status))
-                urb->status = -EREMOTEIO;
+                        !status))
+                status = -EREMOTEIO;
 
         unmap_urb_for_dma(hcd, urb);
-        usbmon_urb_complete(&hcd->self, urb, urb->status);
+        usbmon_urb_complete(&hcd->self, urb, status);
         usb_unanchor_urb(urb);
 
         /* pass ownership to the completion handler */
+        urb->status = status;
         urb->complete (urb);
         atomic_dec (&urb->use_count);
         if (unlikely (urb->reject))
diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h
index 729b7a03acd8..0fc7b95259f5 100644
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -217,7 +217,8 @@ extern void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb);
 
 extern int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags);
 extern int usb_hcd_unlink_urb (struct urb *urb, int status);
-extern void usb_hcd_giveback_urb (struct usb_hcd *hcd, struct urb *urb);
+extern void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb,
+                int status);
 extern void usb_hcd_endpoint_disable (struct usb_device *udev,
                 struct usb_host_endpoint *ep);
 extern int usb_hcd_get_frame_number (struct usb_device *udev);