drm/amd/display: To prevent detecting new sink from spurious HPD

Signed-off-by: Martin Tsai <martin.tsai@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -565,8 +565,6 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason)
 			link->local_sink)
 		return true;
 
-	link_disconnect_sink(link);
-
 	if (new_connection_type != dc_connection_none) {
 		link->type = new_connection_type;
 
@@ -651,16 +649,24 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason)
 		sink_init_data.link = link;
 		sink_init_data.sink_signal = sink_caps.signal;
 
+		if (link->local_sink)	{
+			sink = link->local_sink;
+		} else {
+			link_disconnect_sink(link);
+
+			sink_init_data.link = link;
+			sink_init_data.sink_signal = sink_caps.signal;
+
 			sink = dc_sink_create(&sink_init_data);
 			if (!sink) {
 				DC_ERROR("Failed to create sink!\n");
 				return false;
 			}
-
 			sink->dongle_max_pix_clk = sink_caps.max_hdmi_pixel_clock;
 			sink->converter_disable_audio = converter_disable_audio;
 
 			link->local_sink = sink;
+		}
 
 		edid_status = dm_helpers_read_local_edid(
 				link->ctx,
@@ -752,9 +758,23 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason)
 			memset(link->mst_stream_alloc_table.stream_allocations, 0, sizeof(link->mst_stream_alloc_table.stream_allocations));
 		}
 
+		if (link->local_sink) {
+			sink = link->local_sink;
+			edid_status = dm_helpers_read_local_edid(
+						link->ctx,
+						link,
+						sink);
+			if (edid_status != EDID_OK) {
+				link_disconnect_sink(link);
 				link->type = dc_connection_none;
 				sink_caps.signal = SIGNAL_TYPE_NONE;
 			}
+		} else {
+			link_disconnect_sink(link);
+			link->type = dc_connection_none;
+			sink_caps.signal = SIGNAL_TYPE_NONE;
+		}
+	}
 
 	LINK_INFO("link=%d, dc_sink_in=%p is now %s\n",
 		link->link_index, sink,