+++ /dev/null
---- a/drivers/mtd/mtdconcat.c
-+++ b/drivers/mtd/mtdconcat.c
-@@ -619,7 +619,8 @@ static void concat_sync(struct mtd_info
-
- for (i = 0; i < concat->num_subdev; i++) {
- struct mtd_info *subdev = concat->subdev[i];
-- subdev->sync(subdev);
-+ if (subdev->sync)
-+ subdev->sync(subdev);
- }
- }
-