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

This patch (as973) reorganizes the way dummy-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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 24 insertions, 29 deletions

diff --git a/drivers/usb/gadget/dummy_hcd.c b/drivers/usb/gadget/dummy_hcd.c
index f2b124cf3206..c1af7bab26f0 100644
--- a/drivers/usb/gadget/dummy_hcd.c
+++ b/drivers/usb/gadget/dummy_hcd.c
@@ -1026,16 +1026,10 @@ static int dummy_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
         return rc;
 }
 
-static void maybe_set_status (struct urb *urb, int status)
-{
-        spin_lock (&urb->lock);
-        urb->status = status;
-        spin_unlock (&urb->lock);
-}
-
 /* transfer up to a frame's worth; caller must own lock */
 static int
-transfer (struct dummy *dum, struct urb *urb, struct dummy_ep *ep, int limit)
+transfer(struct dummy *dum, struct urb *urb, struct dummy_ep *ep, int limit,
+                int *status)
 {
         struct dummy_request    *req;
 
@@ -1103,15 +1097,15 @@ top:
                 if (is_short) {
                         if (host_len == dev_len) {
                                 req->req.status = 0;
-                                maybe_set_status (urb, 0);
+                                *status = 0;
                         } else if (to_host) {
                                 req->req.status = 0;
                                 if (dev_len > host_len)
-                                        maybe_set_status (urb, -EOVERFLOW);
+                                        *status = -EOVERFLOW;
                                 else
-                                        maybe_set_status (urb, 0);
+                                        *status = 0;
                         } else if (!to_host) {
-                                maybe_set_status (urb, 0);
+                                *status = 0;
                                 if (host_len > dev_len)
                                         req->req.status = -EOVERFLOW;
                                 else
@@ -1125,9 +1119,8 @@ top:
                                 req->req.status = 0;
                         if (urb->transfer_buffer_length == urb->actual_length
                                         && !(urb->transfer_flags
-                                                & URB_ZERO_PACKET)) {
-                                maybe_set_status (urb, 0);
-                        }
+                                                & URB_ZERO_PACKET))
+                                *status = 0;
                 }
 
                 /* device side completion --> continuable */
@@ -1143,7 +1136,7 @@ top:
                 }
 
                 /* host side completion --> terminate */
-                if (urb->status != -EINPROGRESS)
+                if (*status != -EINPROGRESS)
                         break;
 
                 /* rescan to continue with any other queued i/o */
@@ -1254,6 +1247,7 @@ restart:
                 u8                      address;
                 struct dummy_ep         *ep = NULL;
                 int                     type;
+                int                     status = -EINPROGRESS;
 
                 urb = urbp->urb;
                 if (urb->unlinked)
@@ -1279,7 +1273,7 @@ restart:
                         dev_dbg (dummy_dev(dum),
                                 "no ep configured for urb %p\n",
                                 urb);
-                        maybe_set_status (urb, -EPROTO);
+                        status = -EPROTO;
                         goto return_urb;
                 }
 
@@ -1294,7 +1288,7 @@ restart:
                         /* NOTE: must not be iso! */
                         dev_dbg (dummy_dev(dum), "ep %s halted, urb %p\n",
                                         ep->ep.name, urb);
-                        maybe_set_status (urb, -EPIPE);
+                        status = -EPIPE;
                         goto return_urb;
                 }
                 /* FIXME make sure both ends agree on maxpacket */
@@ -1312,7 +1306,7 @@ restart:
                         w_value = le16_to_cpu(setup.wValue);
                         if (le16_to_cpu(setup.wLength) !=
                                         urb->transfer_buffer_length) {
-                                maybe_set_status (urb, -EOVERFLOW);
+                                status = -EOVERFLOW;
                                 goto return_urb;
                         }
 
@@ -1342,7 +1336,7 @@ restart:
                                 if (setup.bRequestType != Dev_Request)
                                         break;
                                 dum->address = w_value;
-                                maybe_set_status (urb, 0);
+                                status = 0;
                                 dev_dbg (udc_dev(dum), "set_address = %d\n",
                                                 w_value);
                                 value = 0;
@@ -1369,7 +1363,7 @@ restart:
                                         if (value == 0) {
                                                 dum->devstatus |=
                                                         (1 << w_value);
-                                                maybe_set_status (urb, 0);
+                                                status = 0;
                                         }
 
                                 } else if (setup.bRequestType == Ep_Request) {
@@ -1381,7 +1375,7 @@ restart:
                                         }
                                         ep2->halted = 1;
                                         value = 0;
-                                        maybe_set_status (urb, 0);
+                                        status = 0;
                                 }
                                 break;
                         case USB_REQ_CLEAR_FEATURE:
@@ -1391,7 +1385,7 @@ restart:
                                                 dum->devstatus &= ~(1 <<
                                                         USB_DEVICE_REMOTE_WAKEUP);
                                                 value = 0;
-                                                maybe_set_status (urb, 0);
+                                                status = 0;
                                                 break;
                                         default:
                                                 value = -EOPNOTSUPP;
@@ -1406,7 +1400,7 @@ restart:
                                         }
                                         ep2->halted = 0;
                                         value = 0;
-                                        maybe_set_status (urb, 0);
+                                        status = 0;
                                 }
                                 break;
                         case USB_REQ_GET_STATUS:
@@ -1443,7 +1437,7 @@ restart:
                                         urb->actual_length = min (2,
                                                 urb->transfer_buffer_length);
                                         value = 0;
-                                        maybe_set_status (urb, 0);
+                                        status = 0;
                                 }
                                 break;
                         }
@@ -1470,7 +1464,7 @@ restart:
                                         dev_dbg (udc_dev(dum),
                                                 "setup --> %d\n",
                                                 value);
-                                maybe_set_status (urb, -EPIPE);
+                                status = -EPIPE;
                                 urb->actual_length = 0;
                         }
 
@@ -1487,7 +1481,7 @@ restart:
                          * report random errors, to debug drivers.
                          */
                         limit = max (limit, periodic_bytes (dum, ep));
-                        maybe_set_status (urb, -ENOSYS);
+                        status = -ENOSYS;
                         break;
 
                 case PIPE_INTERRUPT:
@@ -1501,12 +1495,12 @@ restart:
                 default:
                 treat_control_like_bulk:
                         ep->last_io = jiffies;
-                        total = transfer (dum, urb, ep, limit);
+                        total = transfer(dum, urb, ep, limit, &status);
                         break;
                 }
 
                 /* incomplete transfer? */
-                if (urb->status == -EINPROGRESS)
+                if (status == -EINPROGRESS)
                         continue;
 
 return_urb:
@@ -1517,6 +1511,7 @@ return_urb:
 
                 usb_hcd_unlink_urb_from_ep(dummy_to_hcd(dum), urb);
                 spin_unlock (&dum->lock);
+                urb->status = status;
                 usb_hcd_giveback_urb (dummy_to_hcd(dum), urb);
                 spin_lock (&dum->lock);