drm/amd/display: Disconnect non-DP with no EDID

[Why]
Active DP dongles return no EDID when dongle
is connected, but VGA display is taken out.
Current driver behavior does not remove the
active display when this happens, and this is
a gap between dongle DTP and dongle behavior.

[How]
For active DP dongles and non-DP scenario,
disconnect sink on detection when no EDID
is read due to timeout.

Signed-off-by: Chris Park <Chris.Park@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: Chris Park

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

@@ -1076,6 +1076,24 @@ static bool dc_link_detect_helper(struct dc_link *link,
 			    dc_is_dvi_signal(link->connector_signal)) {
 				if (prev_sink)
 					dc_sink_release(prev_sink);
+				link_disconnect_sink(link);
+
+				return false;
+			}
+			/*
+			 * Abort detection for DP connectors if we have
+			 * no EDID and connector is active converter
+			 * as there are no display downstream
+			 *
+			 */
+			if (dc_is_dp_sst_signal(link->connector_signal) &&
+				(link->dpcd_caps.dongle_type ==
+						DISPLAY_DONGLE_DP_VGA_CONVERTER ||
+				link->dpcd_caps.dongle_type ==
+						DISPLAY_DONGLE_DP_DVI_CONVERTER)) {
+				if (prev_sink)
+					dc_sink_release(prev_sink);
+				link_disconnect_sink(link);
 
 				return false;
 			}