drm/amd/display: Check and log for function error codes

[WHAT & HOW]
BIOS_CMD_TABLE_REVISION and link_transmitter_control can return error
codes and errors should be reported.

This fixes 3 CHECKED_RETURN issues reported by Coverity.
Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Alex Hung <alex.hung@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/bios/command_table2.c

@@ -227,7 +227,8 @@ static void init_transmitter_control(struct bios_parser *bp)
 	uint8_t frev;
 	uint8_t crev = 0;
 
-	BIOS_CMD_TABLE_REVISION(dig1transmittercontrol, frev, crev);
+	if (!BIOS_CMD_TABLE_REVISION(dig1transmittercontrol, frev, crev))
+		BREAK_TO_DEBUGGER();
 
 	switch (crev) {
 	case 6:

drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c

@@ -1361,7 +1361,10 @@ void dce110_link_encoder_dp_set_lane_settings(
 		cntl.lane_settings = training_lane_set.raw;
 
 		/* call VBIOS table to set voltage swing and pre-emphasis */
-		link_transmitter_control(enc110, &cntl);
+		if (link_transmitter_control(enc110, &cntl) != BP_RESULT_OK) {
+			DC_LOG_ERROR("%s: Failed to execute VBIOS command table!\n", __func__);
+			BREAK_TO_DEBUGGER();
+		}
 	}
 }
 

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.c

@@ -1104,6 +1104,7 @@ void dcn10_link_encoder_dp_set_lane_settings(
 	union dpcd_training_lane_set training_lane_set = { { 0 } };
 	int32_t lane = 0;
 	struct bp_transmitter_control cntl = { 0 };
+	enum bp_result result;
 
 	if (!link_settings) {
 		BREAK_TO_DEBUGGER();
@@ -1138,7 +1139,12 @@ void dcn10_link_encoder_dp_set_lane_settings(
 		cntl.lane_settings = training_lane_set.raw;
 
 		/* call VBIOS table to set voltage swing and pre-emphasis */
-		link_transmitter_control(enc10, &cntl);
+		result = link_transmitter_control(enc10, &cntl);
+
+		if (result != BP_RESULT_OK) {
+			DC_LOG_ERROR("%s: Failed to execute VBIOS command table!\n", __func__);
+			BREAK_TO_DEBUGGER();
+		}
 	}
 }