From 4e1eaa290da54673f9c5ac2c55de10e6478bfc18 Mon Sep 17 00:00:00 2001 From: Melissa Wen Date: Mon, 7 Jul 2025 16:52:05 -0400 Subject: [PATCH] drm/amd/display: Disable CRTC degamma LUT for DCN401 commit 97a0f2b5f4d4afcec34376e4428e157ce95efa71 upstream. In DCN401 pre-blending degamma LUT isn't affecting cursor as in previous DCN version. As this is not the behavior close to what is expected for CRTC degamma LUT, disable CRTC degamma LUT property in this HW. Link: https://gitlab.freedesktop.org/drm/amd/-/issues/4176 --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) 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 e8bdd7f0c4607..db157b38f862b 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 @@ -737,7 +737,16 @@ int amdgpu_dm_crtc_init(struct amdgpu_display_manager *dm, * support programmable degamma anywhere. */ is_dcn = dm->adev->dm.dc->caps.color.dpp.dcn_arch; - drm_crtc_enable_color_mgmt(&acrtc->base, is_dcn ? MAX_COLOR_LUT_ENTRIES : 0, + /* Dont't enable DRM CRTC degamma property for DCN401 since the + * pre-blending degamma LUT doesn't apply to cursor, and therefore + * can't work similar to a post-blending degamma LUT as in other hw + * versions. + * TODO: revisit it once KMS plane color API is merged. + */ + drm_crtc_enable_color_mgmt(&acrtc->base, + (is_dcn && + dm->adev->dm.dc->ctx->dce_version != DCN_VERSION_4_01) ? + MAX_COLOR_LUT_ENTRIES : 0, true, MAX_COLOR_LUT_ENTRIES); drm_mode_crtc_set_gamma_size(&acrtc->base, MAX_COLOR_LEGACY_LUT_ENTRIES); -- 2.47.3