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@xxxxxxxxxxxxxxx> Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx> --- drivers/mtd/nand/raw/nand_base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c index f28c3a5..4a73f73 100644 --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/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]; -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation