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xhci: detect stop endpoint race using pending timer instead of counter.

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A counter was used to find out if the stop endpoint completion raced with
the stop endpoint timeout timer. This was needed in case the stop ep
completion failed to delete the timer as it was running on anoter cpu.

The EP_STOP_CMD_PENDING flag was not enough as a new stop endpoint command
may be queued between the command completion and timeout function, which
would set the flag back.

Instead of the separate counter that was used we can detect the race by
checking both the STOP_EP_PENDING flag and timer_pending in the timeout
function.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathias Nyman
2017-01-23 14:19:53 +02:00
committed by Greg Kroah-Hartman
parent 9983a5fc39
commit f99265965b
3 changed files with 11 additions and 18 deletions
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1
drivers/usb/host/xhci.h
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@@ -924,7 +924,6 @@ struct xhci_virt_ep {
unsigned int stopped_stream;
/* Watchdog timer for stop endpoint command to cancel URBs */
struct timer_list stop_cmd_timer;
int stop_cmds_pending;
struct xhci_hcd *xhci;
/* Dequeue pointer and dequeue segment for a submitted Set TR Dequeue
* command. We'll need to update the ring's dequeue segment and dequeue