Re: [PATCH] uvcvideo: Don't call vb2 mmap and get_unmapped_area with queue lock held

Bjørn Mork
2015-02-23T09:47:52Z

Laurent Pinchart <laurent.pinchart@ideasonboard.com> writes:

> Bjørn, does this fix the circular locking dependency you have reported in
> "[v3.19-rc7] possible circular locking dependency in uvc_queue_streamoff" ?
> The report mentions involves locks, so I'm not 100% this patch will fix the
> issue.

Sorry, I forgot all about that report after firing it off... Should
have followed it up with some more details.

Grepping my logs now I cannot find this warning at all after the one I
reported. I see it once before (while running 3.19-rc6). So it is
definitely not easily reproducible. And I have a bad feeling the
trigger might involve completely unrelated USB issues...

In any case, thanks for the patch. I will test it for a while and let
you know if the same warning shows ut with it. But based on the rare
occurence, I don't think I ever will be able to positively confirm that
the warning is gone.

Bjørn