The patch below does not apply to the 4.16-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 7ad35721e7d5a5b56a4eddcdd9920c3c1e51ae4c Mon Sep 17 00:00:00 2001

From: "Jerry (Fangzhi) Zuo" Jerry.Zuo@amd.com Date: Tue, 17 Apr 2018 14:39:09 -0400 Subject: [PATCH] drm/amd/display: Check dc_sink every time in MST hotplug

Extended fix to: "Don't read EDID in atomic_check"

Fix issue of missing dc_sink in .mode_valid in hot plug routine.

Need to check dc_sink everytime in .get_modes hook after checking edid, since edid is not getting removed in hot unplug but dc_sink doesn't.

Signed-off-by: Jerry (Fangzhi) Zuo Jerry.Zuo@amd.com Reviewed-by: Roman Li Roman.Li@amd.com Reviewed-by: Harry Wentland Harry.Wentland@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c index 8c1d084429dc..ace9ad578ca0 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c @@ -226,10 +226,6 @@ static int dm_dp_mst_get_modes(struct drm_connector *connector)

if (!aconnector->edid) { struct edid *edid; - struct dc_sink *dc_sink; - struct dc_sink_init_data init_params = { - .link = aconnector->dc_link, - .sink_signal = SIGNAL_TYPE_DISPLAY_PORT_MST }; edid = drm_dp_mst_get_edid(connector, &aconnector->mst_port->mst_mgr, aconnector->port);

if (!edid) { @@ -240,11 +236,17 @@ static int dm_dp_mst_get_modes(struct drm_connector *connector) }

aconnector->edid = edid; + }

+ if (!aconnector->dc_sink) { + struct dc_sink *dc_sink; + struct dc_sink_init_data init_params = { + .link = aconnector->dc_link, + .sink_signal = SIGNAL_TYPE_DISPLAY_PORT_MST }; dc_sink = dc_link_add_remote_sink( aconnector->dc_link, - (uint8_t *)edid, - (edid->extensions + 1) * EDID_LENGTH, + (uint8_t *)aconnector->edid, + (aconnector->edid->extensions + 1) * EDID_LENGTH, &init_params);

dc_sink->priv = aconnector; @@ -252,7 +254,7 @@ static int dm_dp_mst_get_modes(struct drm_connector *connector)

if (aconnector->dc_sink) amdgpu_dm_add_sink_to_freesync_module( - connector, edid); + connector, aconnector->edid); }

drm_mode_connector_update_edid_property(