On Mon, 10 Jul 2017 12:37:26 +0200
Miquel Raynal <miquel.ray...@free-electrons.com> wrote:
> Fix nand core lack of OOB layout when:
> - the NFC driver does not provide any OOB layout,
> - ECC operations are disabled (using NAND_ECC_NONE).
> Using this configuration leads to a crash during the probe.
>
> Add layout functions for small and large pages with mainly free bytes
> plus reserved space for bad block markers.
>
> Check the configuration and eventually assign this OOB layout in
> nand_scan_tail().
>
> Bad block markers position was extracted from the existing OOB layouts
> by assigning as free all the bytes marked as ECC.
>
> Signed-off-by: Miquel Raynal <miquel.ray...@free-electrons.com>
> ---
> drivers/mtd/nand/nand_base.c | 75
> +++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 74 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> index c5221795a1e8..28ff58e4385f 100644
> --- a/drivers/mtd/nand/nand_base.c
> +++ b/drivers/mtd/nand/nand_base.c
> @@ -53,7 +53,45 @@ static int nand_get_device(struct mtd_info *mtd, int
> new_state);
> static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
> struct mtd_oob_ops *ops);
>
> -/* Define default oob placement schemes for large and small page devices */
> +/*
> + * Define default OOB placement schemes for:
> + * - no ECC or software ECC
> + * - small or large page devices
> + */
> +static int nand_ooblayout_ecc_sp_bbm_only(struct mtd_info *mtd, int section,
> + struct mtd_oob_region *oobregion)
> +{
> + return -ERANGE;
> +}
> +
> +static int nand_ooblayout_free_sp_bbm_only(struct mtd_info *mtd, int section,
> + struct mtd_oob_region *oobregion)
> +{
> + if (section > 1)
> + return -ERANGE;
> +
> + if (!section) {
> + if (mtd->oobsize == 16) {
> + oobregion->offset = 0;
> + oobregion->length = 4;
> + } else {
> + oobregion->offset = 0;
> + oobregion->length = 5;
> + }
> + } else {
> + oobregion->offset = 6;
> + oobregion->length = mtd->oobsize - oobregion->offset;
> + }
> +
> + return 0;
> +}
> +
> +const struct mtd_ooblayout_ops nand_ooblayout_sp_bbm_only_ops = {
> + .ecc = nand_ooblayout_ecc_sp_bbm_only,
Actually, you don't have to implement ->ecc() in this case, just leave
it to NULL, the core takes care of returning -ENOTSUPP in this case [1].
[1]http://elixir.free-electrons.com/linux/latest/source/drivers/mtd/mtdcore.c#L1143
