+Brian
On Tue, 2 May 2017 12:19:00 +0200
Alexander Couzens <lynxis@xxxxxxx> wrote:
> The old 1-bit hamming layout requires ECC data to be placed at a
> fixed offset, and not necessarily at the end of the OOB area.
> Add this old layout back in order to fix legacy setups.
>
> Fixes: 41b207a70d3a ("mtd: nand: implement the default mtd_ooblayout_ops")
> CC: Stable <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Alexander Couzens <lynxis@xxxxxxx>
Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Brian, maybe you can consider taking this patch directly in
l2-mtd/master before preparing your PR to Linus (if you're happy with
the patch of course). Otherwise, I'll take it into my tree and send a
fixes PR after 4.12-rc1 is out.
> ---
Alexander, just for the record, you should put your changelog here.
> drivers/mtd/nand/nand_base.c | 70 +++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 69 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> index b0524f8accb6..44c0faf84426 100644
> --- a/drivers/mtd/nand/nand_base.c
> +++ b/drivers/mtd/nand/nand_base.c
> @@ -139,6 +139,74 @@ const struct mtd_ooblayout_ops nand_ooblayout_lp_ops = {
> };
> EXPORT_SYMBOL_GPL(nand_ooblayout_lp_ops);
>
> +/*
> + * Support the old "large page" layout used for 1-bit Hamming ECC where ECC
> + * are placed at a fixed offset.
> + */
> +static int nand_ooblayout_ecc_lp_hamming(struct mtd_info *mtd, int section,
> + struct mtd_oob_region *oobregion)
> +{
> + struct nand_chip *chip = mtd_to_nand(mtd);
> + struct nand_ecc_ctrl *ecc = &chip->ecc;
> +
> + if (section)
> + return -ERANGE;
> +
> + switch (mtd->oobsize) {
> + case 64:
> + oobregion->offset = 40;
> + break;
> + case 128:
> + oobregion->offset = 80;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + oobregion->length = ecc->total;
> + if (oobregion->offset + oobregion->length > mtd->oobsize)
> + return -ERANGE;
> +
> + return 0;
> +}
> +
> +static int nand_ooblayout_free_lp_hamming(struct mtd_info *mtd, int section,
> + struct mtd_oob_region *oobregion)
> +{
> + struct nand_chip *chip = mtd_to_nand(mtd);
> + struct nand_ecc_ctrl *ecc = &chip->ecc;
> + int ecc_offset = 0;
> +
> + if (section < 0 || section > 1)
> + return -ERANGE;
> +
> + switch (mtd->oobsize) {
> + case 64:
> + ecc_offset = 40;
> + break;
> + case 128:
> + ecc_offset = 80;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + if (section == 0) {
> + oobregion->offset = 2;
> + oobregion->length = ecc_offset - 2;
> + } else {
> + oobregion->offset = ecc_offset + ecc->total;
> + oobregion->length = mtd->oobsize - oobregion->offset;
> + }
> +
> + return 0;
> +}
> +
> +const struct mtd_ooblayout_ops nand_ooblayout_lp_hamming_ops = {
> + .ecc = nand_ooblayout_ecc_lp_hamming,
> + .free = nand_ooblayout_free_lp_hamming,
> +};
> +
> static int check_offs_len(struct mtd_info *mtd,
> loff_t ofs, uint64_t len)
> {
> @@ -4653,7 +4721,7 @@ int nand_scan_tail(struct mtd_info *mtd)
> break;
> case 64:
> case 128:
> - mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops);
> + mtd_set_ooblayout(mtd, &nand_ooblayout_lp_hamming_ops);
> break;
> default:
> WARN(1, "No oob scheme defined for oobsize %d\n",