[Intel-gfx] [PATCH v11 08/11] drm/i915/dp: Avoid DSC with output_format YCBCR420

[Nautiyal, Ankit K]

Hi Manasi,

I just realized that there is a newer version of the patch in another 
series for DSC 420 support [1].

I added this patch when I was debugging an issue with PCON + 8k YCbCr420 
only mode, and noticed that we set the output_format first and then 
check for DSC.

Later this patch was pulled in DSC420 series and then got some comments 
and modifications.

So, to avoid having similar change in 2 places, perhaps will drop this 
patch from this series, and collect reviews in [1] for the change.

Currently on [1], the check is outside of intel_dp_supports_dsc(), as a 
separate function explicitly checking for the given output_format, but 
we can discuss and have this inside the mentioned function.

Apologies for the inconvenience.

[1] https://patchwork.freedesktop.org/patch/525903/?series=114246&rev=3 
<https://patchwork.freedesktop.org/patch/525903/?series=114246&rev=3>

Thanks & Regards,

Ankit


On 3/14/2023 11:03 PM, Manasi Navare wrote:
> Since we cannot do DSC with this output format currently, can this 
> check be added as part of the intel_dp_supports_dsc() ?
>
> Regards
> Manasi
>
>
> On Tue, Mar 14, 2023 at 4:07 AM Ankit Nautiyal 
> <ankit.k.nautiyal at intel.com> wrote:
>
>     Currently, DSC with YCBCR420 is not supported.
>     Return -EINVAL when trying with DSC with output_format as YCBCR420.
>
>     Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
>     ---
>      drivers/gpu/drm/i915/display/intel_dp.c | 4 ++++
>      1 file changed, 4 insertions(+)
>
>     diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
>     b/drivers/gpu/drm/i915/display/intel_dp.c
>     index b1431ed175bc..99a5cd370c1f 100644
>     --- a/drivers/gpu/drm/i915/display/intel_dp.c
>     +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>     @@ -1602,6 +1602,10 @@ int intel_dp_dsc_compute_config(struct
>     intel_dp *intel_dp,
>             if (!(intel_dp, pipe_config))
>                     return -EINVAL;
>
>     +       /* Currently DSC with YCBCR420 format is not supported */
>     +       if (pipe_config->output_format ==
>     INTEL_OUTPUT_FORMAT_YCBCR420)
>     +               return -EINVAL;
>     +
>             if (compute_pipe_bpp)
>                     pipe_bpp = intel_dp_dsc_compute_bpp(intel_dp,
>     pipe_config->output_format,
>     conn_state->max_requested_bpc);
>     -- 
>     2.25.1
>