drm/amd/display: follow-up fixes for LUT segmentation

[PATCH 0/2] drm/amd/display: follow-up fixes for LUT segmentation

Posted by Melissa Wen 1 month, 1 week ago

Extend halving distribution for all curves/custom-LUT in a
encode-to-linear operation, not only PQ/SRGB. This fixes failures in IGT
kms_colorop test after [1]. Also use the CM3 degamma helper that
translates curves to hw points for DCN30-based family, not only DCN32,
since the banding issue is present on both.

[1] https://lore.kernel.org/amd-gfx/20260623160112.1636801-1-mwen@igalia.com/

Melissa

Melissa Wen (2):
  drm/amd/display: use halving distribution for all encode-to-linear
    curves
  drm/amd/display: use translate_curve_to_degamma_hw_format on DCN30

 .../amd/display/dc/dcn30/dcn30_cm_common.c    | 34 ++++++-------------
 .../amd/display/dc/hwss/dcn30/dcn30_hwseq.c   | 10 +++---
 2 files changed, 14 insertions(+), 30 deletions(-)

-- 
2.53.0

Re: [PATCH 0/2] drm/amd/display: follow-up fixes for LUT segmentation

Posted by Alex Hung 1 month, 1 week ago

Thanks Melissa.

I tested kms_colorop on DCN3.5 DCN3.14 without any problems. There are 
some comments regarding to commit messages which I replied to each patch.

I will send this patchset to next week's promotion test.

On 8/19/26 10:00, Melissa Wen wrote:
> Extend halving distribution for all curves/custom-LUT in a
> encode-to-linear operation, not only PQ/SRGB. This fixes failures in IGT
> kms_colorop test after [1]. Also use the CM3 degamma helper that
> translates curves to hw points for DCN30-based family, not only DCN32,
> since the banding issue is present on both.
> 
> [1] https://lore.kernel.org/amd-gfx/20260623160112.1636801-1-mwen@igalia.com/
> 
> Melissa
> 
> Melissa Wen (2):
>    drm/amd/display: use halving distribution for all encode-to-linear
>      curves
>    drm/amd/display: use translate_curve_to_degamma_hw_format on DCN30
> 
>   .../amd/display/dc/dcn30/dcn30_cm_common.c    | 34 ++++++-------------
>   .../amd/display/dc/hwss/dcn30/dcn30_hwseq.c   | 10 +++---
>   2 files changed, 14 insertions(+), 30 deletions(-)
>

Re: [PATCH 0/2] drm/amd/display: follow-up fixes for LUT segmentation

Posted by Melissa Wen 1 month, 1 week ago


On 19/08/2026 21:07, Alex Hung wrote:
> Thanks Melissa.
>
> I tested kms_colorop on DCN3.5 DCN3.14 without any problems. There are 
> some comments regarding to commit messages which I replied to each patch.
>
> I will send this patchset to next week's promotion test.

Nice! Thanks!

I sent a v2 addressing your comments in the commit message.
https://lore.kernel.org/amd-gfx/20260820093324.10201-1-mwen@igalia.com/

Regarding the duplicated word `segments`, this follows the same pattern 
in similar color helpers and seems correct to me, since they are in 
different sentences.

Melissa

>
> On 8/19/26 10:00, Melissa Wen wrote:
>> Extend halving distribution for all curves/custom-LUT in a
>> encode-to-linear operation, not only PQ/SRGB. This fixes failures in IGT
>> kms_colorop test after [1]. Also use the CM3 degamma helper that
>> translates curves to hw points for DCN30-based family, not only DCN32,
>> since the banding issue is present on both.
>>
>> [1] 
>> https://lore.kernel.org/amd-gfx/20260623160112.1636801-1-mwen@igalia.com/
>>
>> Melissa
>>
>> Melissa Wen (2):
>>    drm/amd/display: use halving distribution for all encode-to-linear
>>      curves
>>    drm/amd/display: use translate_curve_to_degamma_hw_format on DCN30
>>
>>   .../amd/display/dc/dcn30/dcn30_cm_common.c    | 34 ++++++-------------
>>   .../amd/display/dc/hwss/dcn30/dcn30_hwseq.c   | 10 +++---
>>   2 files changed, 14 insertions(+), 30 deletions(-)
>>
>