drm/amd/display: use low clocks for no plane configs

Stream only configurations do not require DCFCLK, SOCCLK, DPPCLK
or FCLK. They also always allow pstate change.
Reviewed-by: NCharlene Liu <Charlene.Liu@amd.com>
Acked-by: NTom Chung <chiahsuan.chung@amd.com>
Signed-off-by: NDmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dml/dcn31/dcn31_fpu.c

@@ -483,7 +483,7 @@ void dcn31_calculate_wm_and_dlg_fp(
 		int pipe_cnt,
 		int vlevel)
 {
-	int i, pipe_idx, active_dpp_count = 0;
+	int i, pipe_idx, active_hubp_count = 0;
 	double dcfclk = context->bw_ctx.dml.vba.DCFCLKState[vlevel][context->bw_ctx.dml.vba.maxMpcComb];
 
 	dc_assert_fp_enabled();
@@ -529,7 +529,7 @@ void dcn31_calculate_wm_and_dlg_fp(
 			continue;
 
 		if (context->res_ctx.pipe_ctx[i].plane_state)
-			active_dpp_count++;
+			active_hubp_count++;
 
 		pipes[pipe_idx].clks_cfg.dispclk_mhz = get_dispclk_calculated(&context->bw_ctx.dml, pipes, pipe_cnt);
 		pipes[pipe_idx].clks_cfg.dppclk_mhz = get_dppclk_calculated(&context->bw_ctx.dml, pipes, pipe_cnt, pipe_idx);
@@ -547,9 +547,19 @@ void dcn31_calculate_wm_and_dlg_fp(
 	}
 
 	dcn20_calculate_dlg_params(dc, context, pipes, pipe_cnt, vlevel);
-	/* For 31x apu pstate change is only supported if possible in vactive or if there are no active dpps */
+	/* For 31x apu pstate change is only supported if possible in vactive*/
 	context->bw_ctx.bw.dcn.clk.p_state_change_support =
-			context->bw_ctx.dml.vba.DRAMClockChangeSupport[vlevel][context->bw_ctx.dml.vba.maxMpcComb] == dm_dram_clock_change_vactive || !active_dpp_count;
+			context->bw_ctx.dml.vba.DRAMClockChangeSupport[vlevel][context->bw_ctx.dml.vba.maxMpcComb] == dm_dram_clock_change_vactive;
+	/* If DCN isn't making memory requests we can allow pstate change and lower clocks */
+	if (!active_hubp_count) {
+		context->bw_ctx.bw.dcn.clk.socclk_khz = 0;
+		context->bw_ctx.bw.dcn.clk.dppclk_khz = 0;
+		context->bw_ctx.bw.dcn.clk.dcfclk_khz = 0;
+		context->bw_ctx.bw.dcn.clk.dcfclk_deep_sleep_khz = 0;
+		context->bw_ctx.bw.dcn.clk.dramclk_khz = 0;
+		context->bw_ctx.bw.dcn.clk.fclk_khz = 0;
+		context->bw_ctx.bw.dcn.clk.p_state_change_support = true;
+	}
 }
 
 void dcn31_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_params)

drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c

@@ -1228,7 +1228,7 @@ static void dcn32_calculate_dlg_params(struct dc *dc, struct dc_state *context,
 				       display_e2e_pipe_params_st *pipes,
 				       int pipe_cnt, int vlevel)
 {
-	int i, pipe_idx;
+	int i, pipe_idx, active_hubp_count = 0;
 	bool usr_retraining_support = false;
 	bool unbounded_req_enabled = false;
 
@@ -1273,6 +1273,8 @@ static void dcn32_calculate_dlg_params(struct dc *dc, struct dc_state *context,
 	for (i = 0, pipe_idx = 0; i < dc->res_pool->pipe_count; i++) {
 		if (!context->res_ctx.pipe_ctx[i].stream)
 			continue;
+		if (context->res_ctx.pipe_ctx[i].plane_state)
+			active_hubp_count++;
 		pipes[pipe_idx].pipe.dest.vstartup_start = get_vstartup(&context->bw_ctx.dml, pipes, pipe_cnt,
 				pipe_idx);
 		pipes[pipe_idx].pipe.dest.vupdate_offset = get_vupdate_offset(&context->bw_ctx.dml, pipes, pipe_cnt,
@@ -1298,6 +1300,16 @@ static void dcn32_calculate_dlg_params(struct dc *dc, struct dc_state *context,
 		context->res_ctx.pipe_ctx[i].pipe_dlg_param = pipes[pipe_idx].pipe.dest;
 		pipe_idx++;
 	}
+	/* If DCN isn't making memory requests we can allow pstate change and lower clocks */
+	if (!active_hubp_count) {
+		context->bw_ctx.bw.dcn.clk.socclk_khz = 0;
+		context->bw_ctx.bw.dcn.clk.dppclk_khz = 0;
+		context->bw_ctx.bw.dcn.clk.dcfclk_khz = 0;
+		context->bw_ctx.bw.dcn.clk.dcfclk_deep_sleep_khz = 0;
+		context->bw_ctx.bw.dcn.clk.dramclk_khz = 0;
+		context->bw_ctx.bw.dcn.clk.fclk_khz = 0;
+		context->bw_ctx.bw.dcn.clk.p_state_change_support = true;
+	}
 	/*save a original dppclock copy*/
 	context->bw_ctx.bw.dcn.clk.bw_dppclk_khz = context->bw_ctx.bw.dcn.clk.dppclk_khz;
 	context->bw_ctx.bw.dcn.clk.bw_dispclk_khz = context->bw_ctx.bw.dcn.clk.dispclk_khz;