在 2025/12/24 3:44, NÃ colas F. R. A. Prado 写道:
This series implements a plane color pipeline for MediaTek platforms, specifically for MT8195-compatible SoCs. The pipeline is composed of the following blocks: Inverse Gamma -> RGB to RGB Color Space Conversion (R2R CSC) -> Gamma (1D Curve) (3x3 Matrix) (1D Curve) The curves supported by Inverse Gamma are: * scRGB * BT.709
scRGB? That means this HW supports float point format surface, are you sure this is not standard sRGB?
The curves supported by Gamma are: * scRGB * BT.709 * BT.2020 * HLG Given the lack of support for writeback connectors on the MediaTek KMS driver, combined with limited hardware documentation, I haven't been able to verify the correctness of each curve, only that they were visually sane (gamma curves made the image on the display brighter, while inverse gamma made it darker).
Hmmm I don't think this is acceptable. sRGB/scRGB has two transfer functions mentioned in original specification[1]. To keep color accuracy, we need someone from mediatek confirm whether this is piece-wise or pure power 2.2 transfer function, this is already done in original amdgpu color pipeline series, sRGB means piece-wise while also dedicated power 2.2 function exists.
Also +cc Xaver for a review as userspace compositor developer. [1] https://gitlab.freedesktop.org/pq/color-and-hdr/-/issues/30
This series depends on "drm: Color pipeline teardown and follow-up fixes/improvements" [1]. This series was tested on the MT8195-Tomato Chromebook. Regarding the support of color operations in OVL for different SoCs: * it's not supported by MT8183, and presumably also not by older generations * On MT8192 it's supported by ovl0 and ovl_2l0, but not ovl_2l2 (despite the same compatible as ovl_2l0). For this series I'm only enabling it on MT8195 since that's the one where I can readily test. [1] https://lore.kernel.org/all/[email protected]/#t Signed-off-by: Nícolas F. R. A. Prado <[email protected]> --- Nícolas F. R. A. Prado (11): drm/mediatek: Introduce DDP plane_colorops_init() hook drm/mediatek: Initialize colorops when creating plane drm/mediatek: ovl: Add supports_plane_colorops flag drm/mediatek: ovl: Enable per-plane color operations on MT8195 drm/mediatek: ovl: Implement support for Inverse Gamma drm/mediatek: Add plane_colorops_init() DDP hook for OVL drm/colorop: Introduce HLG EOTF drm/mediatek: ovl: Implement support for Gamma drm/colorop: Introduce 3x3 Matrix drm/mediatek: ovl: Enable support for R2R Color Space Conversion drm/mediatek: Check 3x3 Matrix colorop has DATA set drivers/gpu/drm/drm_atomic.c | 1 + drivers/gpu/drm/drm_atomic_uapi.c | 3 + drivers/gpu/drm/drm_colorop.c | 22 +++ drivers/gpu/drm/mediatek/mtk_crtc.c | 36 +++- drivers/gpu/drm/mediatek/mtk_ddp_comp.c | 1 + drivers/gpu/drm/mediatek/mtk_ddp_comp.h | 2 + drivers/gpu/drm/mediatek/mtk_disp_drv.h | 1 + drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 287 ++++++++++++++++++++++++++++++++ include/drm/drm_colorop.h | 13 ++ include/uapi/drm/drm_mode.h | 16 ++ 10 files changed, 381 insertions(+), 1 deletion(-) --- base-commit: 1783cdadb70e74a30dfee250f8c2dc13b4e61128 change-id: 20251219-mtk-ovl-pre-blend-colorops-95b7b2883d95 Best regards,
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