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SubjectRe: [PATCH] mtd: core: handle flashes without OTP gracefully
Date
On 7/2/21 12:38 PM, Michael Walle wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> There are flash drivers which registers the OTP callbacks although the
> flash doesn't support OTP regions and return -ENODATA for these
> callbacks if there is no OTP. If this happens, the probe of the whole

why do they register the OTP callback if they don't support OTP?

> flash will fail. Fix it by handling the ENODATA return code and skip
> the OTP region nvmem setup.
>
> Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support")
> Reported-by: Guenter Roeck <linux@roeck-us.net>
> Signed-off-by: Michael Walle <michael@walle.cc>
> ---
> drivers/mtd/mtdcore.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index b5ccd3037788..6881d1423dd6 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -880,7 +880,10 @@ static int mtd_otp_nvmem_add(struct mtd_info *mtd)
>
> if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) {
> size = mtd_otp_size(mtd, true);
> - if (size < 0)
> + /* ENODATA means there is no OTP region */
> + if (size == -ENODATA)

If no OTP data, maybe it's more appropriate for the clients to just
return a retlen of 0.


> + size = 0;
> + else if (size < 0)
> return size;
>
> if (size > 0) {
> @@ -896,7 +899,10 @@ static int mtd_otp_nvmem_add(struct mtd_info *mtd)
>
> if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) {
> size = mtd_otp_size(mtd, false);
> - if (size < 0) {
> + /* ENODATA means there is no OTP region */
> + if (size == -ENODATA) {
> + size = 0;
> + } else if (size < 0) {
> err = size;
> goto err;
> }
> --
> 2.20.1
>
>
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/
>

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