Re: [PATCH v3 00/11] YUV conversion colorop with amdgpu and VKMS

[Robert Mader <robert.mader@collabora.com>]

Hi,

in a related discussion in 
https://lore.kernel.org/dri-devel/d42d5750-f3c5-4e2b-baa3-514b87e59e86@linux.intel.com/ 
Maarten suggested that - given that the new Fixed Matrix colorop 
effectively provides a drop-in replacement for the legacy properties - 
it would be nice to have a helper that automatically provides support 
for the legacy properties for drivers implementing the new color op. 
That'd allow drivers a cleaner switch to the new API, keeping legacy 
support for free.

Harry, WDYT, would that be an option for the two implementations here?

Best regards

On 23.06.26 18:48, Harry Wentland wrote:
> When we merged the drm_plane color pipeline API the major gap
> that existed was the lack of a YUV to RGB conversion colorop.
> We deprecated any legacy drm_plane color properties, which
> means that the COLOR_RANGE and COLOR_ENCODING properties can't
> be used with the COLOR_PIPELINE property on a drm_plane. In
> practice this means that we can't use a COLOR_PIPELINE on
> YCbCr encoded framebuffers.
>
> This patchset expands on the Fixed Matrix colorop proposed by Chaitanya
> and adds limited range variants of the YCbCr to RGB conversions.
>
> His full patchset can be found at
> https://patchwork.freedesktop.org/patch/709860
>
> This code has been tested with IGT and an experimental KWin branch.
>
> IGT branch:
> https://gitlab.freedesktop.org/hwentland/igt-gpu-tools/-/tree/yuv-fm-colorop
>
> KWin branch used for testing:
> https://invent.kde.org/hwentlan/kwin/-/tree/yuv-fm-colorop
>
> The kernel branch containing these changes, based on drm-misc-next
> can be found at:
> https://gitlab.freedesktop.org/hwentland/linux/-/tree/yuv-fm-colorop
>
> Further background on this work can be found at:
> https://hwentland.github.io/2026/03/10/plane-color-pipeline-csc-3d-lut-kwin.html
>
> v3:
> - base on Chaitanya's updated patch and rename code accordingly
>    to Fixed_Matrix instead of CSC Fixed-Function
>
> v2:
> - use Chaitanya's CSC_FF block for named matrices
>
> Cc: Alex Hung <alex.hung@amd.com>
> Cc: Daniel Stone <daniels@collabora.com>
> Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
> Cc: Uma Shankar <uma.shankar@intel.com>
> Cc: Louis Chauvet <louis.chauvet@bootlin.com>
> Cc: Melissa Wen <mwen@igalia.com>
> Cc: Simon Ser <contact@emersion.fr>
> Cc: Robert Mader <robert.mader@collabora.com>
>
> Chaitanya Kumar Borah (1):
>    drm/colorop: Add DRM_COLOROP_FIXED_MATRIX
>
> Harry Wentland (10):
>    drm/colorop: Add limited-range YUV-to-RGB fixed matrix enum values
>    drm/vkms: Add fixed matrix colorop to color pipeline
>    drm/vkms: Add atomic check and matrix handling for fixed matrix
>      colorop
>    drm/amd/display: Add fixed matrix colorop to color pipeline
>    drm/amd/display: Implement fixed matrix colorop color space mapping
>    drm/amd/display: Use GAMCOR for first TF if YUV conversion is needed
>    drm/amd/display: Check actual state during commit_tail
>    drm/amd/display: Set color_space to plane_infos
>    drm/amd/display: Set COLOR_SPACE_SRGB when fixed matrix colorop is
>      bypassed
>    drm/amd/display: Force GAMCOR for subsampled surfaces with
>      PQ/Gamma22/HLG
>
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |  14 ++-
>   .../amd/display/amdgpu_dm/amdgpu_dm_color.c   |  91 +++++++++++++-
>   .../amd/display/amdgpu_dm/amdgpu_dm_colorop.c |  27 ++++-
>   .../amd/display/amdgpu_dm/amdgpu_dm_colorop.h |   1 +
>   .../amd/display/modules/color/color_gamma.c   |   3 +-
>   drivers/gpu/drm/drm_atomic.c                  |   4 +
>   drivers/gpu/drm/drm_atomic_uapi.c             |   4 +
>   drivers/gpu/drm/drm_colorop.c                 | 109 +++++++++++++++++
>   drivers/gpu/drm/vkms/vkms_colorop.c           |  66 +++++++---
>   drivers/gpu/drm/vkms/vkms_composer.c          |   6 +
>   drivers/gpu/drm/vkms/vkms_plane.c             |  68 ++++++++++-
>   include/drm/drm_colorop.h                     | 114 ++++++++++++++++++
>   include/uapi/drm/drm_mode.h                   |  12 ++
>   13 files changed, 487 insertions(+), 32 deletions(-)
>
> --
> 2.54.0
>
-- 
Robert Mader
Consultant Software Developer

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