diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 3a0d557146c7..bf0410403a6f 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3638,6 +3638,7 @@ static int run(struct mddev *mddev)
 
 		if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
 			discard_supported = true;
+		first = 0;
 	}
 
 	if (mddev->queue) {