Re: [PATCH RFC v2 00/20] Introduce support for post-blend color pipeline

[Harry Wentland <harry.wentland@amd.com>]

On 2025-09-17 20:43, Nícolas F. R. A. Prado wrote:
> This series is based on "Color Pipeline API w/ VKMS" [1]. It reuses the
> same concept of a color pipeline API but for the post-blend stage
> instead of pre-blend, by attaching the COLOR_PIPELINE property to the
> CRTC rather than a plane.
> 
> The patches in the series first implement the necessary changes in the
> DRM core to allow for post-blend color pipelines and expose it through
> the uAPI, and then implement support in both the MediaTek KMS driver and
> in VKMS.
> 
> This series has been tested with IGT, with the "Support post-blend color
> pipeline API" series [2] applied, on top of VKMS, as well as with
> Weston, with a WIP branch [3], on a MT8195-Tomato Chromebook, where both
> gamma LUT and CTM color transformations have been simultaneously
> configured in hardware through the API and validated (test commits for
> weston at [4] and for kernel at [5]).

Thanks for this work. Great to see the concepts translate well
to drm_crtc.

I haven't looked at the Mediatek or VKMS patches but left some
comments on the core patches.

Patches 1-2, 8-12 are
Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Harry

> 
> [1] https://lore.kernel.org/all/20250815035047.3319284-1-alex.hung@amd.com/
> [2] https://lore.kernel.org/igt-dev/20250912-post-blend-colorops-v1-0-83fc62420cba@collabora.com/T/#t
> [3] https://gitlab.collabora.com/nfraprado/weston/-/tree/post-blend-colorops?ref_type=heads
> [4] https://gitlab.collabora.com/nfraprado/weston/-/tree/post-blend-color-pipeline-lut-ctm-test?ref_type=tags
> [5] https://gitlab.collabora.com/nfraprado/linux/-/tree/debug-ctm-lut-data-post-blend-colorop?ref_type=tags
> 
> Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
> ---
> Changes in v2:
> - Split core DRM changes for post-blend color pipelines from single
>    commit into smaller changes
> - Added post-blend color pipeline support in VKMS
> - Introduced driver cap, and made client cap depend on it (daniels)
> - Made deprecated color props (GAMMA_LUT, DEGAMMA_LUT, CTM) available as
>    read-only when post-blend color pipelines are enabled (daniels)
> - Created colorop_modeset_lock/unlock to commonize locking pattern for
>    colorops (louis.chauvet)
> - Added helper for post-blend 1D curve colorop creation
> - Link to v1: https://lore.kernel.org/r/20250822-mtk-post-blend-color-pipeline-v1-0-a9446d4aca82@collabora.com
> 
> ---
> Nícolas F. R. A. Prado (20):
>        drm/crtc: Add color pipeline to CRTC state
>        drm/colorop: Allow parenting colorop to CRTC
>        drm: Factor out common color_pipeline property initialization code
>        drm/crtc: Add COLOR_PIPELINE property
>        drm: Introduce DRM_CAP_POST_BLEND_COLOR_PIPELINE
>        drm: Introduce DRM_CLIENT_CAP_POST_BLEND_COLOR_PIPELINE
>        drm/atomic: Pass post_blend_color_pipeline client cap to atomic check
>        drm/atomic: Print the color pipeline as part of the CRTC state print
>        drm/colorop: Factor out common paths from colorops helpers
>        drm/colorop: Introduce colorop helpers for crtc
>        drm/colorop: Export drm_colorop_cleanup() so drivers can extend it
>        drm/crtc: Track post-blend color pipeline client cap in drm_crtc_state
>        drm/mediatek: Support post-blend colorops for gamma and ctm
>        drm/mediatek: ccorr: Support post-blend color pipeline API
>        drm/mediatek: gamma: Support post-blend color pipeline API
>        drm/mediatek: Set post-blend color pipeline driver cap
>        drm/vkms: Rename existing color pipeline helpers to contain "pre_blend"
>        drm/vkms: Prepare pre_blend_color_transform() for post-blend pipelines
>        drm/vkms: Introduce support for post-blend color pipeline
>        drm/vkms: Set post-blend color pipeline driver cap
> 
>   drivers/gpu/drm/drm_atomic.c              |   9 +-
>   drivers/gpu/drm/drm_atomic_uapi.c         |  65 +++++++-
>   drivers/gpu/drm/drm_colorop.c             | 245 ++++++++++++++++++++++++------
>   drivers/gpu/drm/drm_connector.c           |   1 +
>   drivers/gpu/drm/drm_crtc.c                |  77 ++++++++++
>   drivers/gpu/drm/drm_crtc_internal.h       |   6 +
>   drivers/gpu/drm/drm_ioctl.c               |  12 ++
>   drivers/gpu/drm/drm_mode_object.c         |   9 ++
>   drivers/gpu/drm/drm_plane.c               |  36 +----
>   drivers/gpu/drm/mediatek/mtk_crtc.c       | 208 ++++++++++++++++++++++++-
>   drivers/gpu/drm/mediatek/mtk_ddp_comp.c   |   6 +-
>   drivers/gpu/drm/mediatek/mtk_ddp_comp.h   |   2 +
>   drivers/gpu/drm/mediatek/mtk_disp_ccorr.c | 100 ++++++++++--
>   drivers/gpu/drm/mediatek/mtk_disp_drv.h   |   6 +-
>   drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 107 ++++++++++---
>   drivers/gpu/drm/mediatek/mtk_drm_drv.c    |   3 +-
>   drivers/gpu/drm/vkms/vkms_colorop.c       | 106 ++++++++++++-
>   drivers/gpu/drm/vkms/vkms_composer.c      |  13 +-
>   drivers/gpu/drm/vkms/vkms_crtc.c          |   1 +
>   drivers/gpu/drm/vkms/vkms_drv.c           |   3 +-
>   drivers/gpu/drm/vkms/vkms_drv.h           |   3 +-
>   drivers/gpu/drm/vkms/vkms_plane.c         |   2 +-
>   include/drm/drm_atomic.h                  |  20 +++
>   include/drm/drm_atomic_uapi.h             |   2 +
>   include/drm/drm_colorop.h                 |  22 ++-
>   include/drm/drm_crtc.h                    |  27 ++++
>   include/drm/drm_drv.h                     |   6 +
>   include/drm/drm_file.h                    |   7 +
>   include/uapi/drm/drm.h                    |  25 +++
>   29 files changed, 994 insertions(+), 135 deletions(-)
> ---
> base-commit: 342e5ee08797cde0e8af30e6110a5dc1cba61e9c
> change-id: 20250730-mtk-post-blend-color-pipeline-498e1a9cc53e
> 
> Best regards,