drm/amd/display: Add code comments clock and encode code

This commit adds some comments to make easier to understand the clock
update for DCN 201, the encode function, and other minor comments.
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Roman Li <roman.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn201/dcn201_clk_mgr.c

@@ -100,7 +100,15 @@ static void dcn201_update_clocks(struct clk_mgr *clk_mgr_base,
 
 	if (clk_mgr_base->clks.dispclk_khz == 0 ||
 	    dc->debug.force_clock_mode & 0x1) {
+		/* this is from resume or boot up, if forced_clock cfg option
+		 * used, we bypass program dispclk and DPPCLK, but need set them
+		 * for S3.
+		 */
+
 		force_reset = true;
+		/* force_clock_mode 0x1:  force reset the clock even it is the
+		 * same clock as long as it is in Passive level.
+		 */
 
 		dcn2_read_clocks_from_hw_dentist(clk_mgr_base);
 	}
@@ -150,11 +158,14 @@ static void dcn201_update_clocks(struct clk_mgr *clk_mgr_base,
 
 	if (dc->config.forced_clocks == false || (force_reset && safe_to_lower)) {
 		if (dpp_clock_lowered) {
+			// if clock is being lowered, increase DTO before lowering refclk
 			dcn20_update_clocks_update_dpp_dto(clk_mgr, context, safe_to_lower);
 			dcn20_update_clocks_update_dentist(clk_mgr, context);
 		} else {
+			// if clock is being raised, increase refclk before lowering DTO
 			if (update_dppclk || update_dispclk)
 				dcn20_update_clocks_update_dentist(clk_mgr, context);
+			// always update dtos unless clock is lowered and not safe to lower
 			dcn20_update_clocks_update_dpp_dto(clk_mgr, context, safe_to_lower);
 		}
 	}

drivers/gpu/drm/amd/display/dc/dcn201/dcn201_hubbub.c

@@ -103,5 +103,5 @@ void hubbub201_construct(struct dcn20_hubbub *hubbub,
 	hubbub->masks = hubbub_mask;
 
 	hubbub->debug_test_index_pstate = 0xB;
-	hubbub->detile_buf_size = 164 * 1024;
+	hubbub->detile_buf_size = 164 * 1024; /* 164KB for DCN2.0 */
 }

drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hpo_dp_stream_encoder.c

@@ -474,6 +474,10 @@ static void dcn31_hpo_dp_stream_enc_update_dp_info_packets(
 				&info_frame->hdrsmd,
 				true);
 
+	/* packetIndex 4 is used for send immediate sdp message, and please
+	 * use other packetIndex (such as 5,6) for other info packet
+	 */
+
 	if (info_frame->adaptive_sync.valid)
 		enc->vpg->funcs->update_generic_info_packet(
 				enc->vpg,

drivers/gpu/drm/amd/display/dc/resource/Makefile

@@ -102,10 +102,6 @@ AMD_DISPLAY_FILES += $(AMD_DAL_RESOURCE_DCN21)
 
 ###############################################################################
 
-###############################################################################
-
-###############################################################################
-
 RESOURCE_DCN30 = dcn30_resource.o
 
 AMD_DAL_RESOURCE_DCN30 = $(addprefix $(AMDDALPATH)/dc/resource/dcn30/,$(RESOURCE_DCN30))
@@ -202,6 +198,4 @@ AMD_DISPLAY_FILES += $(AMD_DAL_RESOURCE_DCN351)
 
 ###############################################################################
 
-###############################################################################
-
 endif