Merge tag 'drm-next-2018-11-02' of git://anongit.freedesktop.org/drm/drm
[muen/linux.git] / drivers / gpu / drm / drm_atomic_helper.c
index 701cb33..d8b526b 100644 (file)
@@ -308,6 +308,26 @@ update_connector_routing(struct drm_atomic_state *state,
                return 0;
        }
 
+       crtc_state = drm_atomic_get_new_crtc_state(state,
+                                                  new_connector_state->crtc);
+       /*
+        * For compatibility with legacy users, we want to make sure that
+        * we allow DPMS On->Off modesets on unregistered connectors. Modesets
+        * which would result in anything else must be considered invalid, to
+        * avoid turning on new displays on dead connectors.
+        *
+        * Since the connector can be unregistered at any point during an
+        * atomic check or commit, this is racy. But that's OK: all we care
+        * about is ensuring that userspace can't do anything but shut off the
+        * display on a connector that was destroyed after its been notified,
+        * not before.
+        */
+       if (drm_connector_is_unregistered(connector) && crtc_state->active) {
+               DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] is not registered\n",
+                                connector->base.id, connector->name);
+               return -EINVAL;
+       }
+
        funcs = connector->helper_private;
 
        if (funcs->atomic_best_encoder)
@@ -352,7 +372,6 @@ update_connector_routing(struct drm_atomic_state *state,
 
        set_best_encoder(state, new_connector_state, new_encoder);
 
-       crtc_state = drm_atomic_get_new_crtc_state(state, new_connector_state->crtc);
        crtc_state->connectors_changed = true;
 
        DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] using [ENCODER:%d:%s] on [CRTC:%d:%s]\n",