This is a note to let you know that I've just added the patch titled
drm/amd/display: enable cursor degamma for DCN3+ DRM legacy gamma
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-amd-display-enable-cursor-degamma-for-dcn3-drm-legacy-gamma.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 57a943ebfcdb4a97fbb409640234bdb44bfa1953 Mon Sep 17 00:00:00 2001
From: Melissa Wen <mwen@xxxxxxxxxx>
Date: Thu, 31 Aug 2023 15:12:28 -0100
Subject: drm/amd/display: enable cursor degamma for DCN3+ DRM legacy gamma
From: Melissa Wen <mwen@xxxxxxxxxx>
commit 57a943ebfcdb4a97fbb409640234bdb44bfa1953 upstream.
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@xxxxxxxxxxxxxxx
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@xxxxxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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) {
--
2.42.0
Patches currently in stable-queue which might be from mwen@xxxxxxxxxx are
queue-5.15/drm-amd-display-enable-cursor-degamma-for-dcn3-drm-legacy-gamma.patch
