From da9492f97cc09b82a6d60661c0c44518cb03804b Mon Sep 17 00:00:00 2001
From: Iswara Nagulendran <inagulen@amd.com>
Date: Wed, 5 Jan 2022 17:56:25 -0500
Subject: drm/amd/display: Disable FEC if DSC not supported for EDP
Git-commit: 9e6a04651e0231c4ad660e1580b40e56d6d5fde5
Patch-mainline: v5.19-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
[WHY]
Screen was seen corrupted for a few ms
when switching both ways. There was also
not enough bandwidth for HDR to be
enabled in HG disabled mode.
This was due to FEC being
enabled although DSC was not supported
or disabled for the EDP.
[HOW]
Check for EDP DSC support in DC caps
or if DSC should be disabled for EDP
before enabling FEC for EDP.
Reviewed-by: Harry Vanzylldejong <harry.vanzylldejong@amd.com>
Reviewed-by: Evgenii Krasnikov <Evgenii.Krasnikov@amd.com>
Reviewed-by: Nicholas Choi <Nicholas.Choi@amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Signed-off-by: Iswara Nagulendran <inagulen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/dc/core/dc_link.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
index 22f2d88fab99..c1a727ff8b1d 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -4663,8 +4663,10 @@ bool dc_link_should_enable_fec(const struct dc_link *link)
link->local_sink->edid_caps.panel_patch.disable_fec)
force_disable = true;
else if (link->connector_signal == SIGNAL_TYPE_EDP
- && link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.
- dsc_support.DSC_SUPPORT == false)
+ && (link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.
+ dsc_support.DSC_SUPPORT == false
+ || link->dc->debug.disable_dsc_edp
+ || !link->dc->caps.edp_dsc_support))
force_disable = true;
return !force_disable && dc_link_is_fec_supported(link);
--
2.38.1