This is a note to let you know that I've just added the patch titled
drm/amd/display: Fix hang/underflow when transitioning to ODM4:1
to the 6.6-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-fix-hang-underflow-when-transitionin.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 002f47c181d83ed09fc8069f732791bbf632315d
Author: Ilya Bakoulin <ilya.bakoulin@xxxxxxx>
Date: Fri Dec 8 12:19:33 2023 -0500
drm/amd/display: Fix hang/underflow when transitioning to ODM4:1
[ Upstream commit e7b2b108cdeab76a7e7324459e50b0c1214c0386 ]
[Why]
Under some circumstances, disabling an OPTC and attempting to reclaim
its OPP(s) for a different OPTC could cause a hang/underflow due to OPPs
not being properly disconnected from the disabled OPTC.
[How]
Ensure that all OPPs are unassigned from an OPTC when it gets disabled.
Reviewed-by: Alvin Lee <alvin.lee2@xxxxxxx>
Acked-by: Wayne Lin <wayne.lin@xxxxxxx>
Signed-off-by: Ilya Bakoulin <ilya.bakoulin@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Stable-dep-of: b4e05bb1dec5 ("drm/amd/display: Clear OPTC mem select on disable")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_optc.c b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_optc.c
index 8abb94f60078f..b1fcc91b65a32 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_optc.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_optc.c
@@ -148,6 +148,13 @@ static bool optc32_disable_crtc(struct timing_generator *optc)
REG_UPDATE(OTG_CONTROL,
OTG_MASTER_EN, 0);
+ REG_UPDATE_5(OPTC_DATA_SOURCE_SELECT,
+ OPTC_SEG0_SRC_SEL, 0xf,
+ OPTC_SEG1_SRC_SEL, 0xf,
+ OPTC_SEG2_SRC_SEL, 0xf,
+ OPTC_SEG3_SRC_SEL, 0xf,
+ OPTC_NUM_OF_INPUT_SEGMENT, 0);
+
REG_UPDATE(CONTROL,
VTG0_ENABLE, 0);
