Hi, On 08/10/2016 10:16 PM, Alan Stern wrote: > On Wed, 10 Aug 2016, Lu Baolu wrote: > >> 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@xxxxxxxxxxxxxxx # 3.15+ >> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> >> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> >> --- >> v1->v2: >> - Set retval to -ETIMEDOUT after timed out >> - Removed the kernel log in patch description >> >> drivers/usb/misc/usbtest.c | 7 ++++--- >> 1 file changed, 4 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c >> index 6b978f0..c273e11 100644 >> --- a/drivers/usb/misc/usbtest.c >> +++ b/drivers/usb/misc/usbtest.c >> @@ -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 (unlikely(!del_timer_sync(&sg_timer))) >> + retval = -ETIMEDOUT; >> + else >> + retval = req->status; >> >> /* FIXME check resulting data pattern */ > I wouldn't bother with the "unlikely()" because this isn't a hot path. > Aside from that, > > Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Thank you. I will remove "unlikely()" in new version. Best regards, Lu Baolu -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html