usb: misc: usbtest: add fix for driver hang

In sg_timeout(), req->status is set to "-ETIMEDOUT" before calling
into usb_sg_cancel(). usb_sg_cancel() will do nothing and return
directly if req->status has been set to a non-zero value. This will
cause driver hang whenever transfer time out is triggered.

This patch fixes this issue. It could be backported to stable kernel
with version later than v3.15.

Cc: stable@vger.kernel.org # 3.15+
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lu Baolu 2016-08-11 10:31:14 +08:00 committed by Greg Kroah-Hartman
parent 224f6e4036
commit 5395875118

View file

@ -585,7 +585,6 @@ static void sg_timeout(unsigned long _req)
{
struct usb_sg_request *req = (struct usb_sg_request *) _req;
req->status = -ETIMEDOUT;
usb_sg_cancel(req);
}
@ -616,8 +615,10 @@ static int perform_sglist(
mod_timer(&sg_timer, jiffies +
msecs_to_jiffies(SIMPLE_IO_TIMEOUT));
usb_sg_wait(req);
del_timer_sync(&sg_timer);
retval = req->status;
if (!del_timer_sync(&sg_timer))
retval = -ETIMEDOUT;
else
retval = req->status;
/* FIXME check resulting data pattern */