imx-drm: Possible regression after update to atomic

[Ying Liu]

Hi Thorsten,

On Sun, Aug 28, 2016 at 6:17 PM, Thorsten Leemhuis
<regressions at leemhuis.info> wrote:
> Lo! Dave, below report made it to the list of regression for 4.8, but
> afaics nothing happened after the initial report. Was it discussed (and
> maybe even fixed?) elsewhere? Or is there some reason why it shouldn't
> be on the list of regressions at all?

We've got a patch set[1] to fix this.

[1] http://www.spinics.net/lists/dri-devel/msg116491.html

Regards,
Liu Ying

>
> Ciao, Thorsten
>
> On 13.08.2016 14:37, Peter Senna Tschudin wrote:
>>
>> d7868cb7ac58640e9c0383205ba31bd6a985cc6f is the last commit that works for me. I'm experiencing black screen after Weston starts in two different i.MX based devices:
>>
>>  - i.MX6 -> arch/arm/boot/dts/imx6q-b850v3.dts
>>  - i.MX53 based device
>>
>> Weston starts, but nothing is shown on screen. fb works fine. Disabling fb on Kconfig or simply commenting out drm_fbdev_cma_init() solves the black screen issue.
>>
>> The tests that are causing the black screen:
>>
>> diff --git a/drivers/gpu/drm/imx/ipuv3-plane.c b/drivers/gpu/drm/imx/ipuv3-plane.c
>> index 4ad67d0..52dc1b7 100644
>> --- a/drivers/gpu/drm/imx/ipuv3-plane.c
>> +++ b/drivers/gpu/drm/imx/ipuv3-plane.c
>> @@ -325,7 +325,7 @@ static int ipu_plane_atomic_check(struct drm_plane *plane,
>>         if (old_fb && (state->src_w != old_state->src_w ||
>>                               state->src_h != old_state->src_h ||
>>                               fb->pixel_format != old_fb->pixel_format))
>> -               return -EINVAL;
>>
>>         eba = drm_plane_state_to_eba(state);
>>
>> @@ -336,7 +336,7 @@ static int ipu_plane_atomic_check(struct drm_plane *plane,
>>                 return -EINVAL;
>>
>>         if (old_fb && fb->pitches[0] != old_fb->pitches[0])
>> -               return -EINVAL;
>>
>>         switch (fb->pixel_format) {
>>         case DRM_FORMAT_YUV420:
>> @@ -372,7 +372,7 @@ static int ipu_plane_atomic_check(struct drm_plane *plane,
>>                         return -EINVAL;
>>
>>                 if (old_fb && old_fb->pitches[1] != fb->pitches[1])
>> -                       return -EINVAL;
>>         }
>>
>> I tried to replace the return -EINVAL by crtc_state->mode_changed = true with no positive results.
>>
>> I'm trying to understand what is the difference with and without fb, but I have no conclusions yet.
>>
>> Hints on what could be the cause here?
>>
>> Thank you,
>>
>> Peter
>>
>> P.S. This is what I get after replacing the return -EINVAL(the mode is correct): https://goo.gl/photos/1eRdcco9GpszgvzM8