From: Brent Taylor Date: Tue, 31 Oct 2017 03:32:45 +0000 (-0500) Subject: mtd: nand: Fix writing mtdoops to nand flash. X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=c8ea49b690eef5c180369a8d132c5e50a74b3acf;p=sagit-ice-cold%2Fkernel_xiaomi_msm8998.git mtd: nand: Fix writing mtdoops to nand flash. commit 30863e38ebeb500a31cecee8096fb5002677dd9b upstream. 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: Signed-off-by: Brent Taylor Signed-off-by: Boris Brezillon Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 54ab48827258..7ba109e8cf88 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -2663,15 +2663,18 @@ 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->priv; + 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;