commit e9893e6fa932f42c90c4ac5849fa9aa0f0f00a34 upstream.

Positive return value from read_oob() is making false BAD blocks. For some of the NAND controllers, OOB bytes will be protected with ECC and read_oob() will return number of bitflips. If there is any bitflip in ECC protected OOB bytes for BAD block status page, then that block is getting treated as BAD.

Fixes: c120e75e0e7d ("mtd: nand: use read_oob() instead of cmdfunc() for bad block check") Cc: stable@vger.kernel.org Signed-off-by: Abhishek Sahu absahu@codeaurora.org Reviewed-by: Miquel Raynal miquel.raynal@bootlin.com Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com [backported to 4.14.y] Signed-off-by: Abhishek Sahu absahu@codeaurora.org ---

This is backported patch for failed patch mentioned in https://www.spinics.net/lists/stable/msg245833.html The failure happened due to file rename.

drivers/mtd/nand/nand_base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 528e04f..d410de3 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -440,7 +440,7 @@ static int nand_block_bad(struct mtd_info *mtd, loff_t ofs)

for (; page < page_end; page++) { res = chip->ecc.read_oob(mtd, chip, page); - if (res) + if (res < 0) return res;

bad = chip->oob_poi[chip->badblockpos];