Messages in this thread Patch in this message | | | From | <> | Subject | Re: [PATCH] mtd: core: handle flashes without OTP gracefully | Date | Sat, 3 Jul 2021 16:42:30 +0000 |
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On 7/3/21 7:08 PM, Michael Walle wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > Am 3. Juli 2021 11:56:14 MESZ schrieb Tudor.Ambarus@microchip.com: >> 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? > > I don't know. But I certainly won't touch that code :p
why? :D
> > >>> 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. > > you mean already checking ENODATA in mtd_otp_size() and return 0. That would also make the hunk below unnecessary. I'll change it.
I've thought about:
diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c index 54f92d09d9cf..9419b33d7238 100644 --- a/drivers/mtd/chips/cfi_cmdset_0001.c +++ b/drivers/mtd/chips/cfi_cmdset_0001.c @@ -2314,7 +2314,7 @@ static int cfi_intelext_otp_walk(struct mtd_info *mtd, loff_t from, size_t len, /* Check that we actually have some OTP registers */ if (!extp || !(extp->FeatureSupport & 64) || !extp->NumProtectionFields) - return -ENODATA; + return 0;
> > -michael > >> >> >>> + 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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