On Fri, 6 Jul 2012 10:37:30 -0400 (EDT) Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Fri, 6 Jul 2012, Laurent Pinchart wrote: > > > Hi Alan, > > > > On Friday 06 July 2012 09:50:30 Alan Stern wrote: > > > On Fri, 6 Jul 2012, Alan Cox wrote: > > > > From: Eric Ding <ericding@xxxxxxxxxxxx> > > > > > > > > working if I turn it on (e.g., guvcview), then shut it off, wait a few > > > > seconds, and then turn it on again. From the second time onward, all I > > > > get is screen noise rather than the expected video images. > > > > > > > > I did a kernel bisection, which revealed the commit that caused the > > > > regression: > > > > > > > > commit e1620d591a75a10b15cf61dbf8243a0b7e6731a2 > > > > Author: Rafael J. Wysocki <rjw@xxxxxxx> > > > > Date: Fri Mar 18 19:55:36 2011 +0100 > > > > > > > > USB: Move runtime PM callbacks to usb_device_pm_ops > > > > > > Can you figure out exactly how that commit caused the problem? As far > > > as I can tell, it should not have made any difference to anything. > > > > That patch has already been pointed out as problematic: > > > > http://www.mail-archive.com/linux-media@xxxxxxxxxxxxxxx/msg48624.html > > > > (CC'ing the relevant people) > > Yes, but we still need to know the reason why. Neither Rafael nor I > has been able to figure out why that commit messed things up. Was the driver doing any dynamic autosuspend at all until that point ? >From the bug report it goes castors up in windows too if a suspend/resume occurs. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
