This is a note to let you know that I've just added the patch titled
drm/amd/display: don't enable DRM CRTC degamma property for DCE
to the 6.0-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-don-t-enable-drm-crtc-degamma-property-for-dce.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0e444a4de6b38c4593a07e4cfb5bf54c40cc79b6 Mon Sep 17 00:00:00 2001
From: Melissa Wen <mwen@xxxxxxxxxx>
Date: Thu, 3 Nov 2022 17:45:00 -0100
Subject: drm/amd/display: don't enable DRM CRTC degamma property for DCE
From: Melissa Wen <mwen@xxxxxxxxxx>
commit 0e444a4de6b38c4593a07e4cfb5bf54c40cc79b6 upstream.
DM maps DRM CRTC degamma to DPP (pre-blending) degamma block, but DCE doesn't
support programmable degamma curve anywhere. Currently, a custom degamma is
accepted by DM but just ignored by DCE driver and degamma correction isn't
actually applied. There is no way to map custom degamma in DCE, therefore, DRM
CRTC degamma property shouldn't be enabled for DCE drivers.
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
Signed-off-by: Melissa Wen <mwen@xxxxxxxxxx>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c
@@ -412,7 +412,7 @@ int amdgpu_dm_crtc_init(struct amdgpu_di
{
struct amdgpu_crtc *acrtc = NULL;
struct drm_plane *cursor_plane;
-
+ bool is_dcn;
int res = -ENOMEM;
cursor_plane = kzalloc(sizeof(*cursor_plane), GFP_KERNEL);
@@ -450,8 +450,14 @@ int amdgpu_dm_crtc_init(struct amdgpu_di
acrtc->otg_inst = -1;
dm->adev->mode_info.crtcs[crtc_index] = acrtc;
- drm_crtc_enable_color_mgmt(&acrtc->base, MAX_COLOR_LUT_ENTRIES,
+
+ /* Don't enable DRM CRTC degamma property for DCE since it doesn't
+ * 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,
true, MAX_COLOR_LUT_ENTRIES);
+
drm_mode_crtc_set_gamma_size(&acrtc->base, MAX_COLOR_LEGACY_LUT_ENTRIES);
return 0;
Patches currently in stable-queue which might be from mwen@xxxxxxxxxx are
queue-6.0/drm-amd-display-don-t-enable-drm-crtc-degamma-property-for-dce.patch
