[PATCH 5.3 168/193] drm/amd/display: add 50us buffer as WA for pstate switch in active

From: Greg Kroah-Hartman
Date: Mon Nov 11 2019 - 13:59:27 EST


From: Jun Lei <Jun.Lei@xxxxxxx>

[ Upstream commit 7c37d399c2b84d4b79de4d512a38373f1d71ab90 ]

Signed-off-by: Jun Lei <Jun.Lei@xxxxxxx>
Reviewed-by: Aric Cyr <Aric.Cyr@xxxxxxx>
Acked-by: Leo Li <sunpeng.li@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/amd/display/dc/dml/dcn20/display_mode_vba_20.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_mode_vba_20.c b/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_mode_vba_20.c
index 649883777f62a..6c6c486b774a4 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_mode_vba_20.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_mode_vba_20.c
@@ -2577,7 +2577,8 @@ static void dml20_DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndPer
mode_lib->vba.MinActiveDRAMClockChangeMargin
+ mode_lib->vba.DRAMClockChangeLatency;

- if (mode_lib->vba.MinActiveDRAMClockChangeMargin > 0) {
+ if (mode_lib->vba.MinActiveDRAMClockChangeMargin > 50) {
+ mode_lib->vba.DRAMClockChangeWatermark += 25;
mode_lib->vba.DRAMClockChangeSupport[0][0] = dm_dram_clock_change_vactive;
} else {
if (mode_lib->vba.SynchronizedVBlank || mode_lib->vba.NumberOfActivePlanes == 1) {
--
2.20.1