The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 30863e38ebeb500a31cecee8096fb5002677dd9b Mon Sep 17 00:00:00 2001
From: Brent Taylor <motobud@xxxxxxxxx>
Date: Mon, 30 Oct 2017 22:32:45 -0500
Subject: [PATCH] mtd: nand: Fix writing mtdoops to nand flash.
When mtdoops calls mtd_panic_write(), it eventually calls
panic_nand_write() in nand_base.c. In order to properly wait for the
nand chip to be ready in panic_nand_wait(), the chip must first be
selected.
When using the atmel nand flash controller, a panic would occur due to
a NULL pointer exception.
Fixes: 2af7c6539931 ("mtd: Add panic_write for NAND flashes")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Brent Taylor <motobud@xxxxxxxxx>
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 4c867115c53b..e48bf8260f54 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2799,15 +2799,18 @@ static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const uint8_t *buf)
{
struct nand_chip *chip = mtd_to_nand(mtd);
+ int chipnr = (int)(to >> chip->chip_shift);
struct mtd_oob_ops ops;
int ret;
- /* Wait for the device to get ready */
- panic_nand_wait(mtd, chip, 400);
-
/* Grab the device */
panic_nand_get_device(chip, mtd, FL_WRITING);
+ chip->select_chip(mtd, chipnr);
+
+ /* Wait for the device to get ready */
+ panic_nand_wait(mtd, chip, 400);
+
memset(&ops, 0, sizeof(ops));
ops.len = len;
ops.datbuf = (uint8_t *)buf;