From: Michael Walle <michael@walle.cc>
To: Tudor.Ambarus@microchip.com, linux-mtd@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com,
linux@roeck-us.net
Subject: Re: [PATCH] mtd: core: handle flashes without OTP gracefully
Date: Sat, 03 Jul 2021 18:08:38 +0200 [thread overview]
Message-ID: <9F46D75C-D00D-4577-A337-7411049EC7D9@walle.cc> (raw)
In-Reply-To: <9bb2acac-aeb8-d2b2-8df0-9acfd972ec5d@microchip.com>
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
>> 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.
-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/
>>
next prev parent reply other threads:[~2021-07-03 16:26 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-02 9:38 [PATCH] mtd: core: handle flashes without OTP gracefully Michael Walle
2021-07-02 13:49 ` Guenter Roeck
2021-07-02 13:53 ` Michael Walle
2021-07-03 9:56 ` Tudor.Ambarus
2021-07-03 16:08 ` Michael Walle [this message]
2021-07-03 16:42 ` Tudor.Ambarus
2021-07-03 17:26 ` Guenter Roeck
2021-07-06 16:29 ` Miquel Raynal
2021-07-06 18:22 ` Guenter Roeck
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