drm/dp_mst: Don't cache EDIDs for physical ports

Caching EDIDs for physical ports prevents updating the EDID if a port
gets reconnected via a Connection Status Notification message, fix this.

Fixes: db1a07956968 ("drm/dp_mst: Handle SST-only branch device case")
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Lyude Paul <lyude@redhat.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210201120145.350258-2-imre.deak@intel.com
(cherry picked from commit 468091531c2e5c49f55d8c6f1d036ce997d24e13)
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index e82b596..da10a43 100644 (file)
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2302,7 +2302,8 @@ drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
        }
 
        if (port->pdt != DP_PEER_DEVICE_NONE &&
-           drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
+           drm_dp_mst_is_end_device(port->pdt, port->mcs) &&
+           port->port_num >= DP_MST_LOGICAL_PORT_0) {
                port->cached_edid = drm_get_edid(port->connector,
                                                 &port->aux.ddc);
                drm_connector_set_tile_property(port->connector);