drm: Don't race connector registration

[linux-2.6-microblaze.git] / drivers / gpu / drm / drm_connector.c

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 5a45262..7a7019a 100644 (file)
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -225,6 +225,7 @@ int drm_connector_init(struct drm_device *dev,
 
        INIT_LIST_HEAD(&connector->probed_modes);
        INIT_LIST_HEAD(&connector->modes);
+       mutex_init(&connector->mutex);
        connector->edid_blob_ptr = NULL;
        connector->status = connector_status_unknown;
 
@@ -359,6 +360,8 @@ void drm_connector_cleanup(struct drm_connector *connector)
                connector->funcs->atomic_destroy_state(connector,
                                                       connector->state);
 
+       mutex_destroy(&connector->mutex);
+
        memset(connector, 0, sizeof(*connector));
 }
 EXPORT_SYMBOL(drm_connector_cleanup);
@@ -374,14 +377,18 @@ EXPORT_SYMBOL(drm_connector_cleanup);
  */
 int drm_connector_register(struct drm_connector *connector)
 {
-       int ret;
+       int ret = 0;
 
-       if (connector->registered)
+       if (!connector->dev->registered)
                return 0;
 
+       mutex_lock(&connector->mutex);
+       if (connector->registered)
+               goto unlock;
+
        ret = drm_sysfs_connector_add(connector);
        if (ret)
-               return ret;
+               goto unlock;
 
        ret = drm_debugfs_connector_add(connector);
        if (ret) {
@@ -397,12 +404,14 @@ int drm_connector_register(struct drm_connector *connector)
        drm_mode_object_register(connector->dev, &connector->base);
 
        connector->registered = true;
-       return 0;
+       goto unlock;
 
 err_debugfs:
        drm_debugfs_connector_remove(connector);
 err_sysfs:
        drm_sysfs_connector_remove(connector);
+unlock:
+       mutex_unlock(&connector->mutex);
        return ret;
 }
 EXPORT_SYMBOL(drm_connector_register);
@@ -415,8 +424,11 @@ EXPORT_SYMBOL(drm_connector_register);
  */
 void drm_connector_unregister(struct drm_connector *connector)
 {
-       if (!connector->registered)
+       mutex_lock(&connector->mutex);
+       if (!connector->registered) {
+               mutex_unlock(&connector->mutex);
                return;
+       }
 
        if (connector->funcs->early_unregister)
                connector->funcs->early_unregister(connector);
@@ -425,6 +437,7 @@ void drm_connector_unregister(struct drm_connector *connector)
        drm_debugfs_connector_remove(connector);
 
        connector->registered = false;
+       mutex_unlock(&connector->mutex);
 }
 EXPORT_SYMBOL(drm_connector_unregister);