diff --git a/[refs] b/[refs]
index c8e6643c23cc..b21d8c932cbc 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b520e412faaaad35641aeedd6059179f9f1b393c
+refs/heads/master: 4d3a8534bdbcf4843fc8ad05c9a81a964fc65237
diff --git a/trunk/drivers/mtd/mtd_blkdevs.c b/trunk/drivers/mtd/mtd_blkdevs.c
index 85a52b3c7698..2f8c202dbd86 100644
--- a/trunk/drivers/mtd/mtd_blkdevs.c
+++ b/trunk/drivers/mtd/mtd_blkdevs.c
@@ -242,9 +242,12 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 	if (new->devnum == -1)
 		new->devnum = last_devnum+1;
 
-	if ((new->devnum << tr->part_bits) > 256) {
+	/* Check that the device and any partitions will get valid
+	 * minor numbers and that the disk naming code below can cope
+	 * with this number. */
+	if (new->devnum > (MINORMASK >> tr->part_bits) ||
+	    (tr->part_bits && new->devnum >= 27 * 26))
 		return -EBUSY;
-	}
 
 	list_add_tail(&new->list, &tr->devs);
  added: