drm/amd/display: Add audio support for DFP type of active branch is DP case

[Why]
Per DP spec, for active protocol convertor adaptor, DP source should enable audio
for DFP type is DP, HDMI or DP++. Current is_dp_active_dongle() checking is not
precise, which treat branch device default as active dongle. As a result, we will
mistakenly disable audio for DFP type is DP case.

[How]
Make is_dp_active_dongle() checking more precise for active dongle types.
Rename active diongle type as SST branch device in case confusion.
Signed-off-by: Dale Zhao <dale.zhao@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Wayne Lin <Wayne.Lin@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/core/dc_link.c

@@ -762,19 +762,20 @@ static bool detect_dp(struct dc_link *link,
 		}
 
 		if (link->type != dc_connection_mst_branch &&
-		    is_dp_active_dongle(link)) {
-			/* DP active dongles */
-			link->type = dc_connection_active_dongle;
+		    is_dp_branch_device(link)) {
+			/* DP SST branch */
+			link->type = dc_connection_sst_branch;
 			if (!link->dpcd_caps.sink_count.bits.SINK_COUNT) {
 				/*
-				 * active dongle unplug processing for short irq
+				 * SST branch unplug processing for short irq
 				 */
 				link_disconnect_sink(link);
 				return true;
 			}
 
-			if (link->dpcd_caps.dongle_type !=
-			    DISPLAY_DONGLE_DP_HDMI_CONVERTER)
+			if (is_dp_active_dongle(link) &&
+				(link->dpcd_caps.dongle_type !=
+					DISPLAY_DONGLE_DP_HDMI_CONVERTER))
 				*converter_disable_audio = true;
 		}
 	} else {
@@ -974,8 +975,8 @@ static bool dc_link_detect_helper(struct dc_link *link,
 					   sizeof(struct dpcd_caps)))
 					same_dpcd = false;
 			}
-			/* Active dongle downstream unplug*/
-			if (link->type == dc_connection_active_dongle &&
+			/* Active SST downstream branch device unplug*/
+			if (link->type == dc_connection_sst_branch &&
 			    link->dpcd_caps.sink_count.bits.SINK_COUNT == 0) {
 				if (prev_sink)
 					/* Downstream unplug */

drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c

@@ -2593,13 +2593,11 @@ static bool allow_hpd_rx_irq(const struct dc_link *link)
 	/*
 	 * Don't handle RX IRQ unless one of following is met:
 	 * 1) The link is established (cur_link_settings != unknown)
-	 * 2) We kicked off MST detection
-	 * 3) We know we're dealing with an active dongle
+	 * 2) We know we're dealing with a branch device, SST or MST
 	 */
 
 	if ((link->cur_link_settings.lane_count != LANE_COUNT_UNKNOWN) ||
-		(link->type == dc_connection_mst_branch) ||
-		is_dp_active_dongle(link))
+		is_dp_branch_device(link))
 		return true;
 
 	return false;
@@ -3164,7 +3162,7 @@ bool dc_link_handle_hpd_rx_irq(struct dc_link *link, union hpd_irq_data *out_hpd
 			*out_link_loss = true;
 	}
 
-	if (link->type == dc_connection_active_dongle &&
+	if (link->type == dc_connection_sst_branch &&
 		hpd_irq_dpcd_data.bytes.sink_cnt.bits.SINK_COUNT
 			!= link->dpcd_sink_count)
 		status = true;
@@ -3214,6 +3212,12 @@ bool is_mst_supported(struct dc_link *link)
 }
 
 bool is_dp_active_dongle(const struct dc_link *link)
+{
+	return (link->dpcd_caps.dongle_type >= DISPLAY_DONGLE_DP_VGA_CONVERTER) &&
+				(link->dpcd_caps.dongle_type <= DISPLAY_DONGLE_DP_HDMI_CONVERTER);
+}
+
+bool is_dp_branch_device(const struct dc_link *link)
 {
 	return link->dpcd_caps.is_branch_dev;
 }

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

@@ -404,7 +404,7 @@ enum dc_connection_type {
 	dc_connection_none,
 	dc_connection_single,
 	dc_connection_mst_branch,
-	dc_connection_active_dongle
+	dc_connection_sst_branch
 };
 
 struct dc_csc_adjustments {

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

@@ -75,6 +75,8 @@ void detect_edp_sink_caps(struct dc_link *link);
 
 bool is_dp_active_dongle(const struct dc_link *link);
 
+bool is_dp_branch_device(const struct dc_link *link);
+
 bool is_edp_ilr_optimization_required(struct dc_link *link, struct dc_crtc_timing *crtc_timing);
 
 void dp_enable_mst_on_sink(struct dc_link *link, bool enable);