Warning at drivers/gpu/drm/drm_atomic_helper.c

[Marek Vasut]

On 01/23/2017 02:10 AM, Fabio Estevam wrote:
> On Sun, Jan 22, 2017 at 12:26 PM, Fabio Estevam <festevam at gmail.com> wrote:
>> On Sat, Jan 21, 2017 at 2:40 PM, Fabio Estevam <festevam at gmail.com> wrote:
>>> Hi,
>>>
>>> Stopping kmscube application on mx6q through CTRL + C sometimes leads
>>> to the following kernel warning:
>>>
>>> ^C[ 3939.785516] ------------[ cut here ]------------
>>> [ 3939.790313] WARNING: CPU: 1 PID: 67 at
>>> drivers/gpu/drm/drm_atomic_helper.c:1032
>>> drm_atomic_helper_wait_for_fences+0xe4/0x104
>>> [ 3939.801626] Modules linked in:
>>> [ 3939.804762] CPU: 1 PID: 67 Comm: kworker/1:1 Tainted: G        W
>>>    4.9.4 #1
>>
>> Just tested 4.9.5 and the kernel warning is gone.
> 
> Actually 4.9.5 shows the same warning.
> 
> If I change .atomic_commit like in 782ea2a493ba90800 ("drm/imx: Switch
> to drm_fb_cma_prepare_fb() helper") from 4.10-rc1
> 
> -       .atomic_commit = imx_drm_atomic_commit,
> +       .atomic_commit = drm_atomic_helper_commit,
> 
> it fixes the problem.
> 
IMHO this will no longer handle the fences correctly and you'll see
rendering artifacts sometimes.

-- 
Best regards,
Marek Vasut