diff --git a/[refs] b/[refs]
index 9cf8958fe08d..53a630d85d19 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5eff3c439d3478ba9e8ba5f8c0aaf6e6fadb6e58
+refs/heads/master: 4ac6875eeb97a49bad7bc8d56b5ec935904fc6e7
diff --git a/trunk/drivers/md/raid5.c b/trunk/drivers/md/raid5.c
index c5439dce0295..baea94f0670a 100644
--- a/trunk/drivers/md/raid5.c
+++ b/trunk/drivers/md/raid5.c
@@ -5529,6 +5529,10 @@ static int run(struct mddev *mddev)
 		 * discard data disk but write parity disk
 		 */
 		stripe = stripe * PAGE_SIZE;
+		/* Round up to power of 2, as discard handling
+		 * currently assumes that */
+		while ((stripe-1) & stripe)
+			stripe = (stripe | (stripe-1)) + 1;
 		mddev->queue->limits.discard_alignment = stripe;
 		mddev->queue->limits.discard_granularity = stripe;
 		/*