[PATCH AUTOSEL 5.10 55/62] drm/amd/display: Disconnect non-DP with no EDID

[Sasha Levin]

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

[ Upstream commit 080039273b126eeb0185a61c045893a25dbc046e ]

[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>
Tested-by: Daniel Wheeler <daniel.wheeler at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 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 f0039599e02f..62778ccea055 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -1049,6 +1049,24 @@ 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;
 			}
-- 
2.30.2