[PATCH] drm/amd/display: reject both non-zero src_x and src_y only for DCN1x

[S, Shirish]

Hi Paul,

On 11/8/2021 2:25 PM, Paul Menzel wrote:
> Dear Shirish,
>
>
> Am 08.11.21 um 09:15 schrieb Shirish S:
>> limit the MPO rejection only for DCN1x as its not required on later
>
> it’s
>
>> versions.
>
> Where is it documented, that it’s not required for later versions?

This is a workaround to avoid system hang & I've verified its not 
required DCN2.0.

We generally don't have documentation for WA's.

Regards,

Shirish S

>
> Shortly describing the implementation is also useful. Something like: 
> Require `fill_dc_scaling_info()` to receive the device to be able to 
> check the version.
>
>> Fixes: d89f6048bdcb ("drm/amd/display: Reject non-zero src_y and 
>> src_x for video planes")
>>
>
> I’d remove the blank line.
>
>> Signed-off-by: Shirish S <shirish.s at amd.com>
>> ---
>>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 20 ++++++++++---------
>>   1 file changed, 11 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c 
>> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> index 1e26d9be8993..26b29d561919 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> @@ -4572,7 +4572,8 @@ static void get_min_max_dc_plane_scaling(struct 
>> drm_device *dev,
>>   }
>>     -static int fill_dc_scaling_info(const struct drm_plane_state 
>> *state,
>> +static int fill_dc_scaling_info(struct amdgpu_device *adev,
>> +                const struct drm_plane_state *state,
>>                   struct dc_scaling_info *scaling_info)
>>   {
>>       int scale_w, scale_h, min_downscale, max_upscale;
>> @@ -4586,7 +4587,8 @@ static int fill_dc_scaling_info(const struct 
>> drm_plane_state *state,
>>       /*
>>        * For reasons we don't (yet) fully understand a non-zero
>>        * src_y coordinate into an NV12 buffer can cause a
>> -     * system hang. To avoid hangs (and maybe be overly cautious)
>> +     * system hang on DCN1x.
>> +     * To avoid hangs (and maybe be overly cautious)
>
> I’d remove the added line break.
>
>>        * let's reject both non-zero src_x and src_y.
>>        *
>>        * We currently know of only one use-case to reproduce a
>> @@ -4594,10 +4596,10 @@ static int fill_dc_scaling_info(const struct 
>> drm_plane_state *state,
>>        * is to gesture the YouTube Android app into full screen
>>        * on ChromeOS.
>>        */
>> -    if (state->fb &&
>> -        state->fb->format->format == DRM_FORMAT_NV12 &&
>> -        (scaling_info->src_rect.x != 0 ||
>> -         scaling_info->src_rect.y != 0))
>> +    if (((adev->ip_versions[DCE_HWIP][0] == IP_VERSION(1, 0, 0)) ||
>> +        (adev->ip_versions[DCE_HWIP][0] == IP_VERSION(1, 0, 1))) &&
>> +        (state->fb && state->fb->format->format == DRM_FORMAT_NV12 &&
>> +        (scaling_info->src_rect.x != 0 || scaling_info->src_rect.y 
>> != 0)))
>>           return -EINVAL;
>>         scaling_info->src_rect.width = state->src_w >> 16;
>> @@ -5503,7 +5505,7 @@ static int fill_dc_plane_attributes(struct 
>> amdgpu_device *adev,
>>       int ret;
>>       bool force_disable_dcc = false;
>>   -    ret = fill_dc_scaling_info(plane_state, &scaling_info);
>> +    ret = fill_dc_scaling_info(adev, plane_state, &scaling_info);
>>       if (ret)
>>           return ret;
>>   @@ -7566,7 +7568,7 @@ static int dm_plane_atomic_check(struct 
>> drm_plane *plane,
>>       if (ret)
>>           return ret;
>>   -    ret = fill_dc_scaling_info(new_plane_state, &scaling_info);
>> +    ret = fill_dc_scaling_info(adev, new_plane_state, &scaling_info);
>>       if (ret)
>>           return ret;
>>   @@ -9014,7 +9016,7 @@ static void amdgpu_dm_commit_planes(struct 
>> drm_atomic_state *state,
>> bundle->surface_updates[planes_count].gamut_remap_matrix = 
>> &dc_plane->gamut_remap_matrix;
>>           }
>>   -        fill_dc_scaling_info(new_plane_state,
>> +        fill_dc_scaling_info(dm->adev, new_plane_state,
>> &bundle->scaling_infos[planes_count]);
>> bundle->surface_updates[planes_count].scaling_info =
>>