drm/amd/display: increase dcn315 pstate change latency

[Why & How]
Update after new measurment came in
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn315/dcn315_clk_mgr.c

@@ -46,6 +46,9 @@
 #define TO_CLK_MGR_DCN315(clk_mgr)\
 	container_of(clk_mgr, struct clk_mgr_dcn315, base)
 
+#define UNSUPPORTED_DCFCLK 10000000
+#define MIN_DPP_DISP_CLK     100000
+
 static int dcn315_get_active_display_cnt_wa(
 		struct dc *dc,
 		struct dc_state *context)
@@ -147,6 +150,9 @@ static void dcn315_update_clocks(struct clk_mgr *clk_mgr_base,
 		}
 	}
 
+	/* Lock pstate by requesting unsupported dcfclk if change is unsupported */
+	if (!new_clocks->p_state_change_support)
+		new_clocks->dcfclk_khz = UNSUPPORTED_DCFCLK;
 	if (should_set_clock(safe_to_lower, new_clocks->dcfclk_khz, clk_mgr_base->clks.dcfclk_khz)) {
 		clk_mgr_base->clks.dcfclk_khz = new_clocks->dcfclk_khz;
 		dcn315_smu_set_hard_min_dcfclk(clk_mgr, clk_mgr_base->clks.dcfclk_khz);
@@ -160,10 +166,10 @@ static void dcn315_update_clocks(struct clk_mgr *clk_mgr_base,
 
 	// workaround: Limit dppclk to 100Mhz to avoid lower eDP panel switch to plus 4K monitor underflow.
 	if (!IS_DIAG_DC(dc->ctx->dce_environment)) {
-		if (new_clocks->dppclk_khz < 100000)
-			new_clocks->dppclk_khz = 100000;
-		if (new_clocks->dispclk_khz < 100000)
-			new_clocks->dispclk_khz = 100000;
+		if (new_clocks->dppclk_khz < MIN_DPP_DISP_CLK)
+			new_clocks->dppclk_khz = MIN_DPP_DISP_CLK;
+		if (new_clocks->dispclk_khz < MIN_DPP_DISP_CLK)
+			new_clocks->dispclk_khz = MIN_DPP_DISP_CLK;
 	}
 
 	if (should_set_clock(safe_to_lower, new_clocks->dppclk_khz, clk_mgr->base.clks.dppclk_khz)) {
@@ -276,7 +282,7 @@ static struct wm_table ddr5_wm_table = {
 		{
 			.wm_inst = WM_A,
 			.wm_type = WM_TYPE_PSTATE_CHG,
-			.pstate_latency_us = 64.0,
+			.pstate_latency_us = 129.0,
 			.sr_exit_time_us = 11.5,
 			.sr_enter_plus_exit_time_us = 14.5,
 			.valid = true,
@@ -284,7 +290,7 @@ static struct wm_table ddr5_wm_table = {
 		{
 			.wm_inst = WM_B,
 			.wm_type = WM_TYPE_PSTATE_CHG,
-			.pstate_latency_us = 64.0,
+			.pstate_latency_us = 129.0,
 			.sr_exit_time_us = 11.5,
 			.sr_enter_plus_exit_time_us = 14.5,
 			.valid = true,
@@ -292,7 +298,7 @@ static struct wm_table ddr5_wm_table = {
 		{
 			.wm_inst = WM_C,
 			.wm_type = WM_TYPE_PSTATE_CHG,
-			.pstate_latency_us = 64.0,
+			.pstate_latency_us = 129.0,
 			.sr_exit_time_us = 11.5,
 			.sr_enter_plus_exit_time_us = 14.5,
 			.valid = true,
@@ -300,7 +306,7 @@ static struct wm_table ddr5_wm_table = {
 		{
 			.wm_inst = WM_D,
 			.wm_type = WM_TYPE_PSTATE_CHG,
-			.pstate_latency_us = 64.0,
+			.pstate_latency_us = 129.0,
 			.sr_exit_time_us = 11.5,
 			.sr_enter_plus_exit_time_us = 14.5,
 			.valid = true,