[PATCH 1/2] mtd: peb: return success for reading/writing 0 bytes

[Johannes Zink]

On Wed, 2022-11-23 at 12:42 +0100, Sascha Hauer wrote:
> Return successfully when mtd_peb_read() or mtd_peb_write() is passed
> a
> zero length so that the callers do not have to handle this case.
> 
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
Tested-by: Johannes Zink <j.zink at pengutronix.de> (i.MX7 with ubi on
NAND Flash)

> ---
>  drivers/mtd/peb.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mtd/peb.c b/drivers/mtd/peb.c
> index 8443ed86bc..a17d42885e 100644
> --- a/drivers/mtd/peb.c
> +++ b/drivers/mtd/peb.c
> @@ -205,10 +205,12 @@ int mtd_peb_read(struct mtd_info *mtd, void
> *buf, int pnum, int offset,
>                 return -EINVAL;
>         if (offset < 0 || offset + len > mtd->erasesize)
>                 return -EINVAL;
> -       if (len <= 0)
> +       if (len < 0)
>                 return -EINVAL;
>         if (mtd_peb_is_bad(mtd, pnum))
>                 return -EINVAL;
> +       if (!len)
> +               return 0;
>  
>         /* Deliberately corrupt the buffer */
>         *((uint8_t *)buf) ^= 0xFF;
> @@ -388,12 +390,14 @@ int mtd_peb_write(struct mtd_info *mtd, const
> void *buf, int pnum, int offset,
>                 return -EINVAL;
>         if (offset < 0 || offset + len > mtd->erasesize)
>                 return -EINVAL;
> -       if (len <= 0)
> +       if (len < 0)
>                 return -EINVAL;
>         if (len % (mtd->writesize >> mtd->subpage_sft))
>                 return -EINVAL;
>         if (mtd_peb_is_bad(mtd, pnum))
>                 return -EINVAL;
> +       if (!len)
> +               return 0;
>  
>         if (mtd_peb_emulate_write_failure()) {
>                 dev_err(&mtd->dev, "Cannot write %d bytes to PEB
> %d:%d (emulated)\n",

-- 
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