[PATCH 08/20] drm/amd/display: Disconnect non-DP with no EDID

[Stylon Wang]

From: Chris Park <Chris.Park at amd.com>

[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 at amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas at amd.com>
Acked-by: Stylon Wang <stylon.wang at amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_link.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
index 81beff4e9434..c07b45c021d5 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -1099,6 +1099,24 @@ 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;
 			}
-- 
2.25.1