drm/amd/display: Allow PState switch in VBLANK one display VACTIVE

[Why]
For certain display configurations we want to allow PSTATE
switch when one display can switch in VACTIVE and the
other display can switch in VBLANK

[How]
Add extra condition to dcn2 pstate support check
Signed-off-by: Alvin Lee <alvin.lee2@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dc.h

@@ -476,6 +476,7 @@ struct dc_debug_options {
 	bool enable_dmcub_surface_flip;
 	bool usbc_combo_phy_reset_wa;
 	bool disable_dsc;
+	bool enable_dram_clock_change_one_display_vactive;
 };
 
 struct dc_debug_data {

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c

@@ -3112,6 +3112,8 @@ static noinline bool dcn20_validate_bandwidth_fp(struct dc *dc,
 	p_state_latency_us = context->bw_ctx.dml.soc.dram_clock_change_latency_us;
 	context->bw_ctx.dml.soc.disable_dram_clock_change_vactive_support =
 		dc->debug.disable_dram_clock_change_vactive_support;
+	context->bw_ctx.dml.soc.allow_dram_clock_one_display_vactive =
+		dc->debug.enable_dram_clock_change_one_display_vactive;
 
 	if (fast_validate) {
 		return dcn20_validate_bandwidth_internal(dc, context, true);

drivers/gpu/drm/amd/display/dc/dml/dcn20/display_mode_vba_20v2.c

@@ -2599,18 +2599,40 @@ static void dml20v2_DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndP
 		}
 	}
 
+	{
+	float SecondMinActiveDRAMClockChangeMarginOneDisplayInVBLank = 999999;
+	int PlaneWithMinActiveDRAMClockChangeMargin = -1;
+
 	mode_lib->vba.MinActiveDRAMClockChangeMargin = 999999;
 	for (k = 0; k < mode_lib->vba.NumberOfActivePlanes; ++k) {
 		if (mode_lib->vba.ActiveDRAMClockChangeLatencyMargin[k]
 				< mode_lib->vba.MinActiveDRAMClockChangeMargin) {
 			mode_lib->vba.MinActiveDRAMClockChangeMargin =
 					mode_lib->vba.ActiveDRAMClockChangeLatencyMargin[k];
+			if (mode_lib->vba.BlendingAndTiming[k] == k) {
+				PlaneWithMinActiveDRAMClockChangeMargin = k;
+			} else {
+				for (j = 0; j < mode_lib->vba.NumberOfActivePlanes; ++j) {
+					if (mode_lib->vba.BlendingAndTiming[k] == j) {
+						PlaneWithMinActiveDRAMClockChangeMargin = j;
+					}
+				}
+			}
 		}
 	}
 
 	mode_lib->vba.MinActiveDRAMClockChangeLatencySupported =
 			mode_lib->vba.MinActiveDRAMClockChangeMargin
 					+ mode_lib->vba.DRAMClockChangeLatency;
+	for (k = 0; k < mode_lib->vba.NumberOfActivePlanes; ++k) {
+		if (!((k == PlaneWithMinActiveDRAMClockChangeMargin) && (mode_lib->vba.BlendingAndTiming[k] == k))
+				&& !(mode_lib->vba.BlendingAndTiming[k] == PlaneWithMinActiveDRAMClockChangeMargin)
+				&& mode_lib->vba.ActiveDRAMClockChangeLatencyMargin[k]
+						< SecondMinActiveDRAMClockChangeMarginOneDisplayInVBLank) {
+			SecondMinActiveDRAMClockChangeMarginOneDisplayInVBLank =
+					mode_lib->vba.ActiveDRAMClockChangeLatencyMargin[k];
+		}
+	}
 
 	if (mode_lib->vba.DRAMClockChangeSupportsVActive &&
 			mode_lib->vba.MinActiveDRAMClockChangeMargin > 60) {
@@ -2629,7 +2651,11 @@ static void dml20v2_DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndP
 			mode_lib->vba.MinActiveDRAMClockChangeMargin > 0) {
 		mode_lib->vba.DRAMClockChangeSupport[0][0] = dm_dram_clock_change_vactive;
 	} else {
-		if (mode_lib->vba.SynchronizedVBlank || mode_lib->vba.NumberOfActivePlanes == 1) {
+		if ((mode_lib->vba.SynchronizedVBlank
+				|| mode_lib->vba.NumberOfActivePlanes == 1
+				|| (SecondMinActiveDRAMClockChangeMarginOneDisplayInVBLank > 0 &&
+						mode_lib->vba.AllowDramClockChangeOneDisplayVactive))
+					&& mode_lib->vba.PrefetchMode[mode_lib->vba.VoltageLevel][mode_lib->vba.maxMpcComb] == 0) {
 			mode_lib->vba.DRAMClockChangeSupport[0][0] = dm_dram_clock_change_vblank;
 			for (k = 0; k < mode_lib->vba.NumberOfActivePlanes; ++k) {
 				if (!mode_lib->vba.AllowDRAMClockChangeDuringVBlank[k]) {
@@ -2641,6 +2667,7 @@ static void dml20v2_DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndP
 			mode_lib->vba.DRAMClockChangeSupport[0][0] = dm_dram_clock_change_unsupported;
 		}
 	}
+	}
 	for (k = 0; k <= mode_lib->vba.soc.num_states; k++)
 		for (j = 0; j < 2; j++)
 			mode_lib->vba.DRAMClockChangeSupport[k][j] = mode_lib->vba.DRAMClockChangeSupport[0][0];

drivers/gpu/drm/amd/display/dc/dml/display_mode_structs.h

@@ -118,6 +118,7 @@ struct _vcs_dpi_soc_bounding_box_st {
 	double urgent_latency_adjustment_fabric_clock_component_us;
 	double urgent_latency_adjustment_fabric_clock_reference_mhz;
 	bool disable_dram_clock_change_vactive_support;
+	bool allow_dram_clock_one_display_vactive;
 };
 
 struct _vcs_dpi_ip_params_st {

drivers/gpu/drm/amd/display/dc/dml/display_mode_vba.c

@@ -224,6 +224,7 @@ static void fetch_socbb_params(struct display_mode_lib *mode_lib)
 	mode_lib->vba.DummyPStateCheck = soc->dram_clock_change_latency_us == soc->dummy_pstate_latency_us;
 	mode_lib->vba.DRAMClockChangeSupportsVActive = !soc->disable_dram_clock_change_vactive_support ||
 			mode_lib->vba.DummyPStateCheck;
+	mode_lib->vba.AllowDramClockChangeOneDisplayVactive = soc->allow_dram_clock_one_display_vactive;
 
 	mode_lib->vba.Downspreading = soc->downspread_percent;
 	mode_lib->vba.DRAMChannelWidth = soc->dram_channel_width_bytes;   // new!

drivers/gpu/drm/amd/display/dc/dml/display_mode_vba.h

@@ -899,6 +899,7 @@ struct vba_vars_st {
 	double BPP;
 	enum odm_combine_policy ODMCombinePolicy;
 	bool UseMinimumRequiredDCFCLK;
+	bool AllowDramClockChangeOneDisplayVactive;
 };
 
 bool CalculateMinAndMaxPrefetchMode(