1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index e17fbdaf874b..71ea0521ea96 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1796,6 +1796,11 @@ int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
                 req_payload.start_slot = cur_slots;
                 if (mgr->proposed_vcpis[i]) {
                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
+                        port = drm_dp_get_validated_port_ref(mgr, port);
+                        if (!port) {
+                                mutex_unlock(&mgr->payload_lock);
+                                return -EINVAL;
+                        }
                         req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
                         req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
                 } else {
@@ -1823,6 +1828,9 @@ int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
                         mgr->payloads[i].payload_state = req_payload.payload_state;
                 }
                 cur_slots += req_payload.num_slots;
+
+                if (port)
+                        drm_dp_put_port(port);
         }
 
         for (i = 0; i < mgr->max_payloads; i++) {
@@ -2128,6 +2136,8 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
 
         if (mgr->mst_primary) {
                 int sret;
+                u8 guid[16];
+
                 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
                 if (sret != DP_RECEIVER_CAP_SIZE) {
                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
@@ -2142,6 +2152,16 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
                         ret = -1;
                         goto out_unlock;
                 }
+
+                /* Some hubs forget their guids after they resume */
+                sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
+                if (sret != 16) {
+                        DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
+                        ret = -1;
+                        goto out_unlock;
+                }
+                drm_dp_check_mstb_guid(mgr->mst_primary, guid);
+
                 ret = 0;
         } else
                 ret = -1;