drm/amd/display: Skip backend validation for virtual monitors

[Why&How]
Virtual monitors are now being validated during set_mode.
Virtual monitors should not undergo backend validation,
as the backend is intended only for physical monitors.
Virtual sinks have no real backend part information and
should be excluded from this validation.

Reviewed-by: Aric Cyr <[email protected]>
Signed-off-by: Chiawen Huang <[email protected]>
Signed-off-by: Tom Chung <[email protected]>
Tested-by: Daniel Wheeler <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: Chiawen Huang

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

@@ -2334,11 +2334,15 @@ enum dc_status dc_commit_streams(struct dc *dc, struct dc_commit_streams_params
 	for (i = 0; i < params->stream_count; i++) {
 		struct dc_stream_state *stream = params->streams[i];
 		struct dc_stream_status *status = dc_stream_get_status(stream);
+		struct dc_sink *sink = stream->sink;
 
 		/* revalidate streams */
-		res = dc_validate_stream(dc, stream);
-		if (res != DC_OK)
-			return res;
+		if (!dc_is_virtual_signal(sink->sink_signal)) {
+			res = dc_validate_stream(dc, stream);
+			if (res != DC_OK)
+				return res;
+		}
+
 
 		dc_stream_log(dc, stream);