Re: [PATCH AUTOSEL 4.9 20/57] media: sta2x11: Add video_device and vb2_queue locks

[Sasha Levin]

On Mon, Sep 17, 2018 at 08:50:27AM -0300, Ezequiel Garcia wrote:
>Hi Sasha,
>
>On Mon, 2018-09-17 at 03:03 +0000, Sasha Levin wrote:
>> From: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
>>
>> [ Upstream commit cd63c0288fd760ce7de247fba618e2bbcfc0c35c ]
>>
>> Currently, this driver does not serialize its video4linux
>> ioctls, which is a bug, as race conditions might appear.
>>
>> In addition, video_device and vb2_queue locks are now both
>> mandatory. Add them, and implement wait_prepare and
>> wait_finish.
>>
>> To stay on the safe side, this commit uses a single mutex
>> for both locks. Better latency can be obtained by separating
>> these if needed.
>>
>> Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
>> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
>> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
>
>Hm, I am not so sure this patch should go to -stable,
>as it's not fixing a real bug we've seen out there.

You don't really need to wait for a report of this happening if you're
certain that this can happen in the "real world". Having a report is not
a prerequisite of inclusion in stable.

However, if you prefer not to, I can just remove it.