[PATCH] mtd: nand: Fix nand_do_read_oob() return value

[PATCH] mtd: nand: Fix nand_do_read_oob() return value

[Miquel Raynal]

Starting from commit 041e4575f034 ("mtd: nand: handle ECC errors in
OOB"), nand_do_read_oob() (from the NAND core) did return 0 or a
negative error, and the MTD layer expected it.

However, the trend for the NAND layer is now to return an error or a
positive number of bitflips. Deciding which status to return to the user
belongs to the MTD layer.

Commit e47f68587b82 ("mtd: check for max_bitflips in mtd_read_oob()")
brought this logic to the mtd_read_oob() function while the status
coming from nand_do_read_oob() (called by the ->ecc.read_oob() hook) was
left unchanged.

Fixes: e47f68587b82 ("mtd: check for max_bitflips in mtd_read_oob()")
Cc: stable@vger.kernel.org
Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
---
 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 469220065b8b..88256b656072 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -3876,7 +3876,7 @@ static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
 	if (mtd->ecc_stats.failed - stats.failed)
 		return -EBADMSG;
 
-	return  mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0;
+	return max_bitflips;
 }
 
 /**
-- 
2.11.0

Re: [PATCH] mtd: nand: Fix nand_do_read_oob() return value

[Miquel RAYNAL]

On Thu, 11 Jan 2018 21:39:58 +0100
Miquel Raynal <miquel.raynal@free-electrons.com> wrote:

> Starting from commit 041e4575f034 ("mtd: nand: handle ECC errors in
> OOB"), nand_do_read_oob() (from the NAND core) did return 0 or a
> negative error, and the MTD layer expected it.
> 
> However, the trend for the NAND layer is now to return an error or a
> positive number of bitflips. Deciding which status to return to the
> user belongs to the MTD layer.
> 
> Commit e47f68587b82 ("mtd: check for max_bitflips in mtd_read_oob()")
> brought this logic to the mtd_read_oob() function while the status
> coming from nand_do_read_oob() (called by the ->ecc.read_oob() hook)
> was left unchanged.
> 
> Fixes: e47f68587b82 ("mtd: check for max_bitflips in mtd_read_oob()")
> Cc: stable@vger.kernel.org
> Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
> ---

Oops, patch untested, will send a v2, sorry for the noise.

Thanks,
Miquèl