[PATCH] cmd: mtd: check if a block has to be skipped or erased

[Mikhail Kshevetskiy]

On 21.10.2022 18:29, Dario Binacchi wrote:
> [External email]
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> As reported by patch [1], the `mtd erase' command should not erase bad
> blocks.
> To force bad block erasing you have to use the `mtd erase.dontskipbad'
> command.
>
> This patch tries to fix the same issue without modifying code taken
> from the linux kernel, in order to make further upgrades easier.
>
> [1] https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fall%2F20221006031501.110290-2-mikhail.kshevetskiy%40iopsys.eu%2F&data=05%7C01%7Cmikhail.kshevetskiy%40iopsys.eu%7C914960325cd74fb7338208dab37913e4%7C7ff78d652de440f586750569e5c7a65d%7C0%7C0%7C638019629853388501%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=6WBTjvbfll%2Boiz5B8q0o%2Bec0bWKCBf5RimWU1hZe61E%3D&reserved=0
> Signed-off-by: Dario Binacchi <dario.binacchi at amarulasolutions.com>
> Suggested-by: Michael Trimarchi <michael at amarulasolutions.com>
> Co-developed-by: Michael Trimarchi <michael at amarulasolutions.com>
> Signed-off-by: Michael Trimarchi <michael at amarulasolutions.com>
> Cc: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
>
> ---
>
>   cmd/mtd.c | 28 ++++++++++++++++++++--------
>   1 file changed, 20 insertions(+), 8 deletions(-)
>
> diff --git a/cmd/mtd.c b/cmd/mtd.c
> index ad5cc9827d55..3330a428c018 100644
> --- a/cmd/mtd.c
> +++ b/cmd/mtd.c
> @@ -434,19 +434,31 @@ static int do_mtd_erase(struct cmd_tbl *cmdtp, int flag, int argc,
>          erase_op.mtd = mtd;
>          erase_op.addr = off;
>          erase_op.len = mtd->erasesize;
> -       erase_op.scrub = scrub;
>
>          while (len) {
> -               ret = mtd_erase(mtd, &erase_op);
> +               if (!scrub) {
> +                       ret = mtd_block_isbad(mtd, erase_op.addr);
> +                       if (ret < 0) {
> +                               printf("Failed to get bad block at 0x%08llx\n",
> +                                      erase_op.addr);
> +                               ret = CMD_RET_FAILURE;
> +                               goto out_put_mtd;
> +                       }
>
> -               if (ret) {
> -                       /* Abort if its not a bad block error */
> -                       if (ret != -EIO)
> -                               break;
> -                       printf("Skipping bad block at 0x%08llx\n",
> -                              erase_op.addr);
> +                       if (ret > 0) {
> +                               printf("Skipping bad block at 0x%08llx\n",
> +                                      erase_op.addr);
> +                               ret = 0;
> +                               len -= mtd->erasesize;
> +                               erase_op.addr += mtd->erasesize;
> +                               continue;
> +                       }
>                  }
>
> +               ret = mtd_erase(mtd, &erase_op);
> +               if (ret)
> +                       break;
> +

You should check for bad block here, otherwise  bad block not marked in 
BBT will terminate erasing with CMD_RET_SUCCESS result.

>                  len -= mtd->erasesize;
>                  erase_op.addr += mtd->erasesize;
>          }
> --
> 2.32.0
>