Patch "mtd: Fix partition alignment check on multi-erasesize devices" has been added to the 4.13-stable tree

This is a note to let you know that I've just added the patch titled

mtd: Fix partition alignment check on multi-erasesize devices

to the 4.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mtd-fix-partition-alignment-check-on-multi-erasesize-devices.patch
and it can be found in the queue-4.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Boris Brezillon <[email protected]>
Date: Mon, 25 Sep 2017 10:19:57 +0200
Subject: mtd: Fix partition alignment check on multi-erasesize devices

From: Boris Brezillon <[email protected]>

commit 7e439681af82984045efc215437ebb2ca8d33a4c upstream.

Commit 1eeef2d7483a ("mtd: handle partitioning on devices with 0 erasesize") introduced a regression on heterogeneous erase region devices. Alignment of the partition was tested against the master eraseblock size which can be bigger than the slave one, thus leading to some partitions being marked as read-only.

Update wr_alignment to match this slave erasesize after this erasesize has been determined by picking the biggest erasesize of all the regions embedded in the MTD partition.

---
 drivers/mtd/mtdpart.c |    8 ++++++++
 1 file changed, 8 insertions(+)

@@ -581,6 +581,14 @@ static struct mtd_part *allocate_partiti
 		slave->mtd.erasesize = parent->erasesize;
 	}
 
+	/*
+	 * Slave erasesize might differ from the master one if the master
+	 * exposes several regions with different erasesize. Adjust
+	 * wr_alignment accordingly.
+	 */
+	if (!(slave->mtd.flags & MTD_NO_ERASE))
+		wr_alignment = slave->mtd.erasesize;
+
 	tmp = slave->offset;
 	remainder = do_div(tmp, wr_alignment);
 	if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {

Patches currently in stable-queue which might be from [email protected] are

queue-4.13/mtd-fix-partition-alignment-check-on-multi-erasesize-devices.patch queue-4.13/mtd-nand-atmel-fix-buffer-overflow-in-atmel_pmecc_user.patch