drm/amd/display: Update DRAM watermark before checking to update TTU

[Why]
In most cases, DRAM watermark is large enough that the result of the
condition to increase TTU doesn't change after DRAM watermark is
increased. However, there is are cases where the condition fails and
becomes true after DRAM watermark is increased. This results in minTTU <
DRAM watermarks which leads to PSR hang since p-state is requested but
not allowed.

[How]
Check whether to update TTU after DRAM watermark is updated.

Signed-off-by: Jaehyun Chung <jaehyun.chung@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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 5bbbafacc72038c8e365727bc270220466f9cc81..922ab7169e5240895acb7a2ec9ccf9d1a62194e9 100644 (file)
--- 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 +2614,7 @@ static void dml20v2_DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndP
 
        if (mode_lib->vba.DRAMClockChangeSupportsVActive &&
                        mode_lib->vba.MinActiveDRAMClockChangeMargin > 60) {
+               mode_lib->vba.DRAMClockChangeWatermark += 25;
 
                for (k = 0; k < mode_lib->vba.NumberOfActivePlanes; ++k) {
                        if (mode_lib->vba.PrefetchMode[mode_lib->vba.VoltageLevel][mode_lib->vba.maxMpcComb] == 0) {
@@ -2622,7 +2623,7 @@ static void dml20v2_DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndP
                                        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 &&
                        mode_lib->vba.MinActiveDRAMClockChangeMargin > 0) {