On 11/25/2016 11:27 AM, Boris Brezillon wrote:
> On Fri, 25 Nov 2016 10:58:26 +0100
> Marek Vasut <marek.vasut@xxxxxxxxx> wrote:
>
>> On 11/25/2016 10:13 AM, Boris Brezillon wrote:
>>> Commit a894cf6c5a82 ("mtd: nand: mxc: switch to mtd_ooblayout_ops")
>>> introduced a bug in the OOB layout description. Even if the driver claims
>>> that 3 ECC bytes are reserved to protect 512 bytes of data, it's actually
>>> 5 ECC bytes to protect 512+6 bytes of data (some OOB bytes are also
>>> protected using extra ECC bytes).
>>>
>>> Fix the mxc_v1_ooblayout_{free,ecc}() functions to reflect this behavior.
>>>
>>> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
>>> Fixes: a894cf6c5a82 ("mtd: nand: mxc: switch to mtd_ooblayout_ops")
>>> Cc: <stable@xxxxxxxxxxxxxxx>
>>> ---
>>> drivers/mtd/nand/mxc_nand.c | 5 ++---
>>> 1 file changed, 2 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
>>> index 61ca020c5272..c19ec4f0983e 100644
>>> --- a/drivers/mtd/nand/mxc_nand.c
>>> +++ b/drivers/mtd/nand/mxc_nand.c
>>> @@ -886,7 +886,7 @@ static int mxc_v1_ooblayout_ecc(struct mtd_info *mtd, int section,
>>> return -ERANGE;
>>>
>>> oobregion->offset = (section * 16) + 6;
>>> - oobregion->length = nand_chip->ecc.bytes;
>>> + oobregion->length = 5;
>>
>> Use a macro instead of hard-coding a value please :)
>
> Ideally, we should change ->eccbytes value in the
> imx27_nand_devtype_data and imx21_nand_devtype_data definitions, but I
> fear it could break other things.
I was wondering about that too :) Break what things ?
> I'll define a macro.
Thanks!
>>
>>> return 0;
>>> }
>>> @@ -908,8 +908,7 @@ static int mxc_v1_ooblayout_free(struct mtd_info *mtd, int section,
>>> oobregion->length = 4;
>>> }
>>> } else {
>>> - oobregion->offset = ((section - 1) * 16) +
>>> - nand_chip->ecc.bytes + 6;
>>> + oobregion->offset = ((section - 1) * 16) + 5 + 6;
>>
>> DTTO here, the math here is cryptic enough.
>>
>>> if (section < nand_chip->ecc.steps)
>>> oobregion->length = (section * 16) + 6 -
>>> oobregion->offset;
>>>
>>
>>
>
--
Best regards,
Marek Vasut
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html