drm/amd/display: dcn2 use fixed clocks.

[Description]
dcn2 use fixed clocks and not program DPP CLK or Disp_CLK.
Signed-off-by: Charlene Liu <charlene.liu@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c

@@ -225,19 +225,19 @@ void dcn2_update_clocks(struct clk_mgr *clk_mgr_base,
 
 		update_dispclk = true;
 	}
-
-	if (dpp_clock_lowered) {
-		// if clock is being lowered, increase DTO before lowering refclk
-		dcn20_update_clocks_update_dpp_dto(clk_mgr, context);
-		dcn20_update_clocks_update_dentist(clk_mgr);
-	} else {
-		// if clock is being raised, increase refclk before lowering DTO
-		if (update_dppclk || update_dispclk)
-			dcn20_update_clocks_update_dentist(clk_mgr);
-		if (update_dppclk)
+	if (dc->config.forced_clocks == false) {
+		if (dpp_clock_lowered) {
+			// if clock is being lowered, increase DTO before lowering refclk
 			dcn20_update_clocks_update_dpp_dto(clk_mgr, context);
+			dcn20_update_clocks_update_dentist(clk_mgr);
+		} else {
+			// if clock is being raised, increase refclk before lowering DTO
+			if (update_dppclk || update_dispclk)
+				dcn20_update_clocks_update_dentist(clk_mgr);
+			if (update_dppclk)
+				dcn20_update_clocks_update_dpp_dto(clk_mgr, context);
+		}
 	}
-
 	if (update_dispclk &&
 			dmcu && dmcu->funcs->is_dmcu_initialized(dmcu)) {
 		/*update dmcu for wait_loop count*/

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

@@ -218,6 +218,8 @@ struct dc_config {
 	bool allow_seamless_boot_optimization;
 	bool power_down_display_on_boot;
 	bool edp_not_connected;
+	bool forced_clocks;
+
 };
 
 enum visual_confirm {

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

@@ -2156,7 +2156,10 @@ bool dcn20_validate_bandwidth(struct dc *dc, struct dc_state *context,
 		}
 		if (force_split && context->bw_ctx.dml.vba.NoOfDPP[vlevel][context->bw_ctx.dml.vba.maxMpcComb][pipe_idx] == 1)
 			context->bw_ctx.dml.vba.RequiredDPPCLK[vlevel][context->bw_ctx.dml.vba.maxMpcComb][pipe_idx] /= 2;
-
+		if (dc->config.forced_clocks == true) {
+			context->bw_ctx.dml.vba.RequiredDPPCLK[vlevel][context->bw_ctx.dml.vba.maxMpcComb][pipe_idx] =
+					context->bw_ctx.dml.soc.clock_limits[0].dppclk_mhz;
+		}
 		if (!pipe->top_pipe && !pipe->plane_state && context->bw_ctx.dml.vba.ODMCombineEnabled[pipe_idx]) {
 			hsplit_pipe = find_idle_secondary_pipe(&context->res_ctx, dc->res_pool, pipe);
 			ASSERT(hsplit_pipe);
@@ -2258,6 +2261,10 @@ bool dcn20_validate_bandwidth(struct dc *dc, struct dc_state *context,
 			else
 				pipes[pipe_cnt].pipe.dest.odm_combine = 0;
 		}
+		if (dc->config.forced_clocks) {
+			pipes[pipe_cnt].clks_cfg.dispclk_mhz = context->bw_ctx.dml.soc.clock_limits[0].dispclk_mhz;
+			pipes[pipe_cnt].clks_cfg.dppclk_mhz = context->bw_ctx.dml.soc.clock_limits[0].dppclk_mhz;
+		}
 		pipe_cnt++;
 	}