===================================================================
@@ -574,7 +574,7 @@ __acquires(ps->lock)
/* Now carefully unlink all the marked pending URBs */
rescan:
- list_for_each_entry(as, &ps->async_pending, asynclist) {
+ list_for_each_entry_reverse(as, &ps->async_pending, asynclist) {
if (as->bulk_status == AS_UNLINK) {
as->bulk_status = 0; /* Only once */
urb = as->urb;
@@ -636,7 +636,7 @@ static void destroy_async(struct usb_dev
spin_lock_irqsave(&ps->lock, flags);
while (!list_empty(list)) {
- as = list_entry(list->next, struct async, asynclist);
+ as = list_last_entry(list, struct async, asynclist);
list_del_init(&as->asynclist);
urb = as->urb;
usb_get_urb(urb);
When the kernel unlinks a bunch of URBs for a single endpoint, it should always unlink them in reverse order. This eliminates any possibility that some URB x will be unlinked before it can execute but the following URB x+1 will execute before it can be unlinked. Such an event would be bad, for obvious reasons. Chris Dickens pointed out that usbfs doesn't behave this way when it is unbound from an interface. All pending URBs are cancelled, but in the order of submission. This patch changes the behavior to make the unlinks occur in reverse order. It similarly changes the behavior when usbfs cancels the continuation URBs for a BULK endpoint. Suggested-by: Chris Dickens <christopher.a.dickens@gmail.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> --- This doesn't fix any reported bugs, so I don't think it needs to go into the -stable kernels. [as1929] drivers/usb/core/devio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)