2017-10-31 03:34:54

by Brent Taylor

[permalink] [raw]
Subject: [PATCH v2] mtd: nand: Fix writing mtdoops to nand flash.

From: Brent Taylor <[email protected]>

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.

Signed-off-by: Brent Taylor <[email protected]>
---
Changes in v2:
- drop deselecting the chip
- move select_chip and panic_nand_wait after panic_nand_get_device

drivers/mtd/nand/nand_base.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 12edaae17d81..2093667e2bcb 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2802,12 +2802,16 @@ static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
struct mtd_oob_ops ops;
int ret;

- /* Wait for the device to get ready */
- panic_nand_wait(mtd, chip, 400);
+ int chipnr = (int)(to >> chip->chip_shift);

/* 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;
--
2.14.2


From 1583015603969639319@xxx Fri Nov 03 03:55:23 +0000 2017
X-GM-THRID: 1583015603969639319
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread