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From: Michael Walle <michael@walle.cc>
To: Guenter Roeck <linux@roeck-us.net>
Cc: linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Rob Herring <robh+dt@kernel.org>,
	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Subject: Re: [PATCH v2 5/5] mtd: core: add OTP nvmem provider support
Date: Fri, 02 Jul 2021 00:10:24 +0200	[thread overview]
Message-ID: <f48661d2d54b37db395fb73af8b52359@walle.cc> (raw)
In-Reply-To: <20210701213420.GA1131789@roeck-us.net>

Hi Guenter,

Am 2021-07-01 23:34, schrieb Guenter Roeck:
> Hi,
> 
> On Sat, Apr 24, 2021 at 01:06:08PM +0200, Michael Walle wrote:
>> Flash OTP regions can already be read via user space. Some boards have
>> their serial number or MAC addresses stored in the OTP regions. Add
>> support for them being a (read-only) nvmem provider.
>> 
>> The API to read the OTP data is already in place. It distinguishes
>> between factory and user OTP, thus there are up to two different
>> providers.
>> 
>> Signed-off-by: Michael Walle <michael@walle.cc>
> 
> This patch causes a boot failure with one of my qemu tests.
> With the patch in place, the flash fails to instantiate.
> 
> [    1.156578] Creating 3 MTD partitions on "physmap-flash":
> [    1.157192] 0x000000000000-0x000000040000 : "U-Boot Bootloader"
> [    1.184632] 0x000000040000-0x000000060000 : "U-Boot Environment"
> [    1.201767] 0x000000060000-0x000000800000 : "Flash"
> [    1.222320] Deleting MTD partitions on "physmap-flash":
> [    1.222744] Deleting U-Boot Bootloader MTD partition
> [    1.303597] Deleting U-Boot Environment MTD partition
> [    1.368751] Deleting Flash MTD partition
> [    1.430619] physmap-flash: probe of physmap-flash failed with error 
> -61
> 
> -61 is -ENODATA.
> 
> Other boot tests with different flash chips can still boot.
> Reverting this patch (as well as the follow-up patches) fixes
> the problem.
> 
> I do not know if this is a problem with qemu or a problem with the
> patch, but, as I mentioned, other flash chips do still instantiate.
> 
> Do you have an idea what to look for when I try to track down the 
> problem ?

I'd start by looking at the return code of mtd_otp_size() because that
should be the only function which communicates with the flash at probe
time.

Can you share how to reproduce that problem? Like the qemu commandline
and involved images?

-michael

______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

WARNING: multiple messages have this Message-ID (diff)
From: Michael Walle <michael@walle.cc>
To: Guenter Roeck <linux@roeck-us.net>
Cc: linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Rob Herring <robh+dt@kernel.org>,
	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Subject: Re: [PATCH v2 5/5] mtd: core: add OTP nvmem provider support
Date: Fri, 02 Jul 2021 00:10:24 +0200	[thread overview]
Message-ID: <f48661d2d54b37db395fb73af8b52359@walle.cc> (raw)
In-Reply-To: <20210701213420.GA1131789@roeck-us.net>

Hi Guenter,

Am 2021-07-01 23:34, schrieb Guenter Roeck:
> Hi,
> 
> On Sat, Apr 24, 2021 at 01:06:08PM +0200, Michael Walle wrote:
>> Flash OTP regions can already be read via user space. Some boards have
>> their serial number or MAC addresses stored in the OTP regions. Add
>> support for them being a (read-only) nvmem provider.
>> 
>> The API to read the OTP data is already in place. It distinguishes
>> between factory and user OTP, thus there are up to two different
>> providers.
>> 
>> Signed-off-by: Michael Walle <michael@walle.cc>
> 
> This patch causes a boot failure with one of my qemu tests.
> With the patch in place, the flash fails to instantiate.
> 
> [    1.156578] Creating 3 MTD partitions on "physmap-flash":
> [    1.157192] 0x000000000000-0x000000040000 : "U-Boot Bootloader"
> [    1.184632] 0x000000040000-0x000000060000 : "U-Boot Environment"
> [    1.201767] 0x000000060000-0x000000800000 : "Flash"
> [    1.222320] Deleting MTD partitions on "physmap-flash":
> [    1.222744] Deleting U-Boot Bootloader MTD partition
> [    1.303597] Deleting U-Boot Environment MTD partition
> [    1.368751] Deleting Flash MTD partition
> [    1.430619] physmap-flash: probe of physmap-flash failed with error 
> -61
> 
> -61 is -ENODATA.
> 
> Other boot tests with different flash chips can still boot.
> Reverting this patch (as well as the follow-up patches) fixes
> the problem.
> 
> I do not know if this is a problem with qemu or a problem with the
> patch, but, as I mentioned, other flash chips do still instantiate.
> 
> Do you have an idea what to look for when I try to track down the 
> problem ?

I'd start by looking at the return code of mtd_otp_size() because that
should be the only function which communicates with the flash at probe
time.

Can you share how to reproduce that problem? Like the qemu commandline
and involved images?

-michael

  reply	other threads:[~2021-07-01 22:11 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-24 11:06 [PATCH v2 0/5] mtd: core: OTP nvmem provider support Michael Walle
2021-04-24 11:06 ` Michael Walle
2021-04-24 11:06 ` [PATCH v2 1/5] nvmem: core: allow specifying of_node Michael Walle
2021-04-24 11:06   ` Michael Walle
2021-05-10 10:44   ` Miquel Raynal
2021-05-10 10:44     ` Miquel Raynal
2021-04-24 11:06 ` [PATCH v2 2/5] dt-bindings: mtd: add YAML schema for the generic MTD bindings Michael Walle
2021-04-24 11:06   ` Michael Walle
2021-05-10 10:44   ` Miquel Raynal
2021-05-10 10:44     ` Miquel Raynal
2021-05-17 15:12     ` Rob Herring
2021-05-17 15:12       ` Rob Herring
2021-05-17 17:21       ` Michael Walle
2021-05-17 17:21         ` Michael Walle
2021-04-24 11:06 ` [PATCH v2 3/5] dt-bindings: mtd: add OTP bindings Michael Walle
2021-04-24 11:06   ` Michael Walle
2021-05-03 17:12   ` Rob Herring
2021-05-03 17:12     ` Rob Herring
2021-05-10 10:44   ` Miquel Raynal
2021-05-10 10:44     ` Miquel Raynal
2021-04-24 11:06 ` [PATCH v2 4/5] dt-bindings: mtd: spi-nor: add otp property Michael Walle
2021-04-24 11:06   ` Michael Walle
2021-05-03 17:12   ` Rob Herring
2021-05-03 17:12     ` Rob Herring
2021-05-10 10:44   ` Miquel Raynal
2021-05-10 10:44     ` Miquel Raynal
2021-04-24 11:06 ` [PATCH v2 5/5] mtd: core: add OTP nvmem provider support Michael Walle
2021-04-24 11:06   ` Michael Walle
2021-05-10 10:43   ` Miquel Raynal
2021-05-10 10:43     ` Miquel Raynal
2021-05-18 18:55   ` [PATCH] mtd: core: Fix freeing of otp_info buffer Jon Hunter
2021-05-18 18:55     ` Jon Hunter
2021-05-18 20:02     ` Michael Walle
2021-05-18 20:02       ` Michael Walle
2021-05-26  9:03     ` Miquel Raynal
2021-05-26  9:03       ` Miquel Raynal
2021-07-01 21:34   ` [PATCH v2 5/5] mtd: core: add OTP nvmem provider support Guenter Roeck
2021-07-01 21:34     ` Guenter Roeck
2021-07-01 22:10     ` Michael Walle [this message]
2021-07-01 22:10       ` Michael Walle
2021-07-02  1:55       ` Guenter Roeck
2021-07-02  1:55         ` Guenter Roeck
2021-07-02  9:33         ` Michael Walle
2021-07-02  9:33           ` Michael Walle

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