Re: [PATCH v2 1/2] nand: brcmnand: improve hamming oob layout

Miquel Raynal
2020-05-11T16:34:10Z

Hi Álvaro,

Álvaro Fernández Rojas <noltari@gmail.com> wrote on Mon, 4 May 2020
20:59:44 +0200:

> The current code generates 8 oob sections:
> S1 1-5
> ECC 6-8
> S2 9-15
> S3 16-21
> ECC 22-24
> S4 25-31
> S5 32-37
> ECC 38-40
> S6 41-47
> S7 48-53
> ECC 54-56
> S8 57-63
>
> Change it by merging continuous sections:
> S1 1-5
> ECC 6-8
> S2 9-21
> ECC 22-24
> S3 25-37
> ECC 38-40
> S4 41-53
> ECC 54-56
> S5 57-63
>
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
> ---
> v2: keep original comment and fix correctly skip byte 6 for small-page nand
>
> drivers/mtd/nand/raw/brcmnand/brcmnand.c | 34 +++++++++++++-----------
> 1 file changed, 18 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> index e4e3ceeac38f..767343e0e6e7 100644
> --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> @@ -1100,30 +1100,32 @@ static int brcmnand_hamming_ooblayout_free(struct mtd_info *mtd, int section,
> struct brcmnand_cfg *cfg = &host->hwcfg;
> int sas = cfg->spare_area_size << cfg->sector_size_1k;
> int sectors = cfg->page_size / (512 << cfg->sector_size_1k);
> + u32 next;
>
> - if (section >= sectors * 2)
> + if (section > sectors)
> return -ERANGE;
>
> - oobregion->offset = (section / 2) * sas;
> + next = (section * sas);
> + if (section < sectors)
> + next += 6;
>
> - if (section & 1) {
> - oobregion->offset += 9;
> - oobregion->length = 7;
> + if (section) {
> + oobregion->offset = ((section - 1) * sas) + 9;
> } else {
> - oobregion->length = 6;
> -
> - /* First sector of each page may have BBI */
> - if (!section) {
> - /*
> - * Small-page NAND use byte 6 for BBI while large-page
> - * NAND use byte 0.
> - */
> - if (cfg->page_size > 512)
> - oobregion->offset++;
> - oobregion->length--;
> + /*
> + * Small-page NAND use byte 6 for BBI while large-page
> + * NAND use byte 0.
> + */
> + if (cfg->page_size > 512) {
> + oobregion->offset = 1;
> + } else {
> + oobregion->offset = 0;
> + next--;
> }
> }
>
> + oobregion->length = next - oobregion->offset;
> +
> return 0;
> }
>

I'm fine with the two patches but could you please invert the order and
add Fixes: + Cc: stable tags on both? on "fix hamming oob layout"
please? This way the fix is valid on older versions of the driver an
can be backported easily.

Thanks,
Miquèl