drm/amd/display: Prevent dpcd reads with passive dongles (e6142dd5) · Commits · 戴 / test

[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 <aurabindo.pillai@amd.com> Reviewed-by:

Harry Wentland <Harry.Wentland@amd.com> Acked-by:

Aurabindo Pillai <aurabindo.pillai@amd.com> Signed-off-by:

Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

+11 −6

Original line number	Diff line number	Diff line
		@@ -2008,17 +2008,22 @@ 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;


		drm_connector_update_edid_property(connector,
		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 {

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