From 57a943ebfcdb4a97fbb409640234bdb44bfa1953 Mon Sep 17 00:00:00 2001
From: Melissa Wen <mwen@igalia.com>
Date: Thu, 31 Aug 2023 15:12:28 -0100
Subject: [PATCH] drm/amd/display: enable cursor degamma for DCN3+ DRM legacy gamma
Git-commit: 57a943ebfcdb4a97fbb409640234bdb44bfa1953
Patch-mainline: v6.6-rc1
References: git-fixes
Alt-commit: fabd2165d11649ecca5012d786a62ac149e9d83f
For DRM legacy gamma, AMD display manager applies implicit sRGB degamma
using a pre-defined sRGB transfer function. It works fine for DCN2
family where degamma ROM and custom curves go to the same color block.
But, on DCN3+, degamma is split into two blocks: degamma ROM for
pre-defined TFs and `gamma correction` for user/custom curves and
degamma ROM settings doesn't apply to cursor plane. To get DRM legacy
gamma working as expected, enable cursor degamma ROM for implict sRGB
degamma on HW with this configuration.
Cc: stable@vger.kernel.org
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2803
Fixes: 96b020e2163f ("drm/amd/display: check attr flag before set cursor degamma on DCN3+")
Signed-off-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c | 7 +++++++
1 file changed, 7 insertions(+)
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 2198df96ed6f..cc74dd69acf2 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
@@ -1269,6 +1269,13 @@ void amdgpu_dm_plane_handle_cursor_update(struct drm_plane *plane,
attributes.rotation_angle = 0;
attributes.attribute_flags.value = 0;
+ /* Enable cursor degamma ROM on DCN3+ for implicit sRGB degamma in DRM
+ * legacy gamma setup.
+ */
+ if (crtc_state->cm_is_degamma_srgb &&
+ adev->dm.dc->caps.color.dpp.gamma_corr)
+ attributes.attribute_flags.bits.ENABLE_CURSOR_DEGAMMA = 1;
+
attributes.pitch = afb->base.pitches[0] / afb->base.format->cpp[0];
if (crtc_state->stream) {
--
2.35.3