From a4fa2355e0add57253468ef13bd08f11285f3b6e Mon Sep 17 00:00:00 2001 From: Alex Hung Date: Fri, 27 Feb 2026 12:30:38 -0700 Subject: drm/amd/display: Enable DEGAMMA and reject COLOR_PIPELINE+DEGAMMA_LUT [WHAT] Create DEGAMMA properties even if color pipeline is enabled, and enforce the mutual exclusion in atomic check by rejecting any commit that attempts to enable both COLOR_PIPELINE on the plane and DEGAMMA_LUT on the CRTC simultaneously. Fixes: 18a4127e9315 ("drm/amd/display: Disable CRTC degamma when color pipeline is enabled") Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4963 Reviewed-by: Melissa Wen Reviewed-by: Harry Wentland Signed-off-by: Alex Hung Signed-off-by: Alex Deucher (cherry picked from commit 196a6aa727f1f15eb54dda5e60a41543ea9397ee) --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c | 16 ++++++++-------- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c | 8 ++++++++ 2 files changed, 16 insertions(+), 8 deletions(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c index 130190e8a1b2..304437c2284d 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c @@ -765,15 +765,15 @@ int amdgpu_dm_crtc_init(struct amdgpu_display_manager *dm, dm->adev->mode_info.crtcs[crtc_index] = acrtc; /* Don't enable DRM CRTC degamma property for - * 1. Degamma is replaced by color pipeline. - * 2. DCE since it doesn't support programmable degamma anywhere. - * 3. DCN401 since pre-blending degamma LUT doesn't apply to cursor. + * 1. DCE since it doesn't support programmable degamma anywhere. + * 2. DCN401 since pre-blending degamma LUT doesn't apply to cursor. + * Note: DEGAMMA properties are created even if the primary plane has the + * COLOR_PIPELINE property. User space can use either the DEGAMMA properties + * or the COLOR_PIPELINE property. An atomic commit which attempts to enable + * both is rejected. */ - if (plane->color_pipeline_property) - has_degamma = false; - else - has_degamma = dm->adev->dm.dc->caps.color.dpp.dcn_arch && - dm->adev->dm.dc->ctx->dce_version != DCN_VERSION_4_01; + has_degamma = dm->adev->dm.dc->caps.color.dpp.dcn_arch && + dm->adev->dm.dc->ctx->dce_version != DCN_VERSION_4_01; drm_crtc_enable_color_mgmt(&acrtc->base, has_degamma ? MAX_COLOR_LUT_ENTRIES : 0, true, MAX_COLOR_LUT_ENTRIES); diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c index 70587e5a8d46..127207e18dcb 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c @@ -1256,6 +1256,14 @@ static int amdgpu_dm_plane_atomic_check(struct drm_plane *plane, if (ret) return ret; + /* Reject commits that attempt to use both COLOR_PIPELINE and CRTC DEGAMMA_LUT */ + if (new_plane_state->color_pipeline && new_crtc_state->degamma_lut) { + drm_dbg_atomic(plane->dev, + "[PLANE:%d:%s] COLOR_PIPELINE and CRTC DEGAMMA_LUT cannot be enabled simultaneously\n", + plane->base.id, plane->name); + return -EINVAL; + } + ret = amdgpu_dm_plane_fill_dc_scaling_info(adev, new_plane_state, &scaling_info); if (ret) return ret; -- cgit v1.2.3