Hi,

in a related discussion in https://lore.kernel.org/dri-devel/[email protected]/ 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 <[email protected]>
Cc: Daniel Stone <[email protected]>
Cc: Chaitanya Kumar Borah <[email protected]>
Cc: Uma Shankar <[email protected]>
Cc: Louis Chauvet <[email protected]>
Cc: Melissa Wen <[email protected]>
Cc: Simon Ser <[email protected]>
Cc: Robert Mader <[email protected]>

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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