From: Miquel Raynal <miquel.raynal@bootlin.com>
To: James Hilliard <james.hilliard1@gmail.com>
Cc: Richard Weinberger <richard@nod.at>,
Vignesh Raghavendra <vigneshr@ti.com>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Chen-Yu Tsai <wens@kernel.org>,
Jernej Skrabec <jernej.skrabec@gmail.com>,
Samuel Holland <samuel@sholland.org>,
Maxime Ripard <mripard@kernel.org>,
linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] mtd: rawnand: sunxi: support randomized OOB formats
Date: Fri, 04 Sep 2026 17:27:13 +0200 [thread overview]
Message-ID: <878q5h11gu.fsf@bootlin.com> (raw)
In-Reply-To: <CADvTj4oW8Hxv_b5vWM5pbeB3wEO-WoqhLwyinCTFPNR6wTHYmQ@mail.gmail.com> (James Hilliard's message of "Fri, 4 Sep 2026 11:17:46 -0400")
On 04/09/2026 at 11:17:46 -04, James Hilliard <james.hilliard1@gmail.com> wrote:
> On Fri, Sep 4, 2026 at 8:42 AM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
>>
>> On 10/08/2026 at 17:04:50 -06, James Hilliard <james.hilliard1@gmail.com> wrote:
>>
>> > The controller randomizer covers the bad block marker along with the
>> > rest of the OOB data. The driver currently compensates the marker bytes
>> > before writes and after reads so that they remain plain on flash.
>> >
>> > Allwinner NAND firmware instead stores the marker through the
>> > randomizer. Media using that format appears to contain bad blocks unless
>> > the randomizer is enabled while reading the marker.
>> >
>> > Honor the allwinner,randomized-oob property by unconditionally enabling
>> > page scrambling and leaving the marker in the randomizer data stream.
>> > Keep the existing plain marker behavior when the property is absent.
>> > This changes marker handling on all supported controllers; the H6/H616
>> > protected user-data placement is handled separately.
>>
>> But I think the reason why this has never been done is because it just
>> breaks raw accesses, including the BBT reads. I don't think this is
>> handled, is it?
>
> From my understanding raw access bypasses randomization entirely.
yes, so the implementation you propose is invalid, raw reads shall
show the BBM. And also, when accessing a BBT, it is made in raw mode,
without randomization, and hence totally fail. This cannot fly!
WARNING: multiple messages have this Message-ID (diff)
From: Miquel Raynal <miquel.raynal@bootlin.com>
To: James Hilliard <james.hilliard1@gmail.com>
Cc: Richard Weinberger <richard@nod.at>,
Vignesh Raghavendra <vigneshr@ti.com>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Chen-Yu Tsai <wens@kernel.org>,
Jernej Skrabec <jernej.skrabec@gmail.com>,
Samuel Holland <samuel@sholland.org>,
Maxime Ripard <mripard@kernel.org>,
linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] mtd: rawnand: sunxi: support randomized OOB formats
Date: Fri, 04 Sep 2026 17:27:13 +0200 [thread overview]
Message-ID: <878q5h11gu.fsf@bootlin.com> (raw)
In-Reply-To: <CADvTj4oW8Hxv_b5vWM5pbeB3wEO-WoqhLwyinCTFPNR6wTHYmQ@mail.gmail.com> (James Hilliard's message of "Fri, 4 Sep 2026 11:17:46 -0400")
On 04/09/2026 at 11:17:46 -04, James Hilliard <james.hilliard1@gmail.com> wrote:
> On Fri, Sep 4, 2026 at 8:42 AM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
>>
>> On 10/08/2026 at 17:04:50 -06, James Hilliard <james.hilliard1@gmail.com> wrote:
>>
>> > The controller randomizer covers the bad block marker along with the
>> > rest of the OOB data. The driver currently compensates the marker bytes
>> > before writes and after reads so that they remain plain on flash.
>> >
>> > Allwinner NAND firmware instead stores the marker through the
>> > randomizer. Media using that format appears to contain bad blocks unless
>> > the randomizer is enabled while reading the marker.
>> >
>> > Honor the allwinner,randomized-oob property by unconditionally enabling
>> > page scrambling and leaving the marker in the randomizer data stream.
>> > Keep the existing plain marker behavior when the property is absent.
>> > This changes marker handling on all supported controllers; the H6/H616
>> > protected user-data placement is handled separately.
>>
>> But I think the reason why this has never been done is because it just
>> breaks raw accesses, including the BBT reads. I don't think this is
>> handled, is it?
>
> From my understanding raw access bypasses randomization entirely.
yes, so the implementation you propose is invalid, raw reads shall
show the BBM. And also, when accessing a BBT, it is made in raw mode,
without randomization, and hence totally fail. This cannot fly!
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Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/
next prev parent reply other threads:[~2026-09-04 15:27 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-10 23:04 [PATCH 0/3] mtd: rawnand: sunxi: support the Allwinner randomized OOB format James Hilliard
2026-08-10 23:04 ` James Hilliard
2026-08-10 23:04 ` [PATCH 1/3] dt-bindings: mtd: sunxi: Add randomized OOB flag James Hilliard
2026-08-10 23:04 ` James Hilliard
2026-08-10 23:04 ` [PATCH 2/3] mtd: rawnand: sunxi: support randomized OOB formats James Hilliard
2026-08-10 23:04 ` James Hilliard
2026-09-04 14:42 ` Miquel Raynal
2026-09-04 14:42 ` Miquel Raynal
2026-09-04 15:17 ` James Hilliard
2026-09-04 15:17 ` James Hilliard
2026-09-04 15:27 ` Miquel Raynal [this message]
2026-09-04 15:27 ` Miquel Raynal
2026-09-04 16:31 ` James Hilliard
2026-09-04 16:31 ` James Hilliard
2026-08-10 23:04 ` [PATCH 3/3] mtd: rawnand: sunxi: select the packed H6/H616 OOB layout James Hilliard
2026-08-10 23:04 ` James Hilliard
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