From 95f7f8f1eda1cbe3dca9d53b44acf8e06d2dbd92 Mon Sep 17 00:00:00 2001 From: Aurabindo Pillai Date: Wed, 22 Apr 2020 14:37:33 -0400 Subject: [PATCH] drm/amd/display: Prevent dpcd reads with passive dongles [why] During hotplug, a DP port may be connected to the sink through passive adapter which does not support DPCD reads. Issuing reads without checking for this condition will result in errors [how] Ensure the link is in aux_mode before initiating operation that result in a DPCD read. Signed-off-by: Aurabindo Pillai Reviewed-by: Harry Wentland Acked-by: Aurabindo Pillai Signed-off-by: Alex Deucher --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index a351a3f08fc4c..26e370986c0cc 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -2012,17 +2012,22 @@ void amdgpu_dm_update_connector_after_detect( dc_sink_retain(aconnector->dc_sink); if (sink->dc_edid.length == 0) { aconnector->edid = NULL; - drm_dp_cec_unset_edid(&aconnector->dm_dp_aux.aux); + if (aconnector->dc_link->aux_mode) { + drm_dp_cec_unset_edid( + &aconnector->dm_dp_aux.aux); + } } else { aconnector->edid = - (struct edid *) sink->dc_edid.raw_edid; - + (struct edid *)sink->dc_edid.raw_edid; drm_connector_update_edid_property(connector, - aconnector->edid); - drm_dp_cec_set_edid(&aconnector->dm_dp_aux.aux, - aconnector->edid); + aconnector->edid); + + if (aconnector->dc_link->aux_mode) + drm_dp_cec_set_edid(&aconnector->dm_dp_aux.aux, + aconnector->edid); } + amdgpu_dm_update_freesync_caps(connector, aconnector->edid); update_connector_ext_caps(aconnector); } else { -- 2.39.5