[PATCH 29/35] drm/amd/display: Update TTU properly

[Rodrigo Siqueira]

From: Alvin Lee <alvin.lee2 at amd.com>

[Why]
We need to update TTU properly if DRAMClockChangeWatermark changes. If
TTU < DRAMClockChangeWatermark, we pstate won't be allowed and we will
hang in some PSR cases.

[How]
Update TTU if DramClockChangeWatermark value increases (only if TTU was
dependent on the watermark value on the DRAMClockChangeWatermark value
in the first place).

Signed-off-by: Alvin Lee <alvin.lee2 at amd.com>
Reviewed-by: Jun Lei <Jun.Lei at amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira at amd.com>
Acked-by: Harry Wentland <harry.wentland at amd.com>
---
 .../drm/amd/display/dc/dml/dcn20/display_mode_vba_20v2.c  | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_mode_vba_20v2.c b/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_mode_vba_20v2.c
index 485a9c62ec58..5bbbafacc720 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_mode_vba_20v2.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_mode_vba_20v2.c
@@ -2614,6 +2614,14 @@ static void dml20v2_DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndP
 
 	if (mode_lib->vba.DRAMClockChangeSupportsVActive &&
 			mode_lib->vba.MinActiveDRAMClockChangeMargin > 60) {
+
+		for (k = 0; k < mode_lib->vba.NumberOfActivePlanes; ++k) {
+			if (mode_lib->vba.PrefetchMode[mode_lib->vba.VoltageLevel][mode_lib->vba.maxMpcComb] == 0) {
+				if (mode_lib->vba.DRAMClockChangeWatermark >
+				dml_max(mode_lib->vba.StutterEnterPlusExitWatermark, mode_lib->vba.UrgentWatermark))
+					mode_lib->vba.MinTTUVBlank[k] += 25;
+			}
+		}
 		mode_lib->vba.DRAMClockChangeWatermark += 25;
 		mode_lib->vba.DRAMClockChangeSupport[0][0] = dm_dram_clock_change_vactive;
 	} else if (mode_lib->vba.DummyPStateCheck &&
-- 
2.25.0