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From:   Miquel Raynal <miquel.raynal@bootlin.com>
To:     Christian Marangi <ansuelsmth@gmail.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Manivannan Sadhasivam <mani@kernel.org>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        linux-arm-msm@vger.kernel.org, linux-mtd@lists.infradead.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v8 2/3] mtd: nand: raw: qcom_nandc: add support for unprotected spare data pages
Date:   Fri, 17 Jun 2022 08:31:29 +0200
Message-Id: <20220617063129.446718-1-miquel.raynal@bootlin.com>
In-Reply-To: <20220616001835.24393-3-ansuelsmth@gmail.com>
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On Thu, 2022-06-16 at 00:18:34 UTC, Christian Marangi wrote:
> IPQ8064 nand have special pages where a different layout scheme is used.
> These special page are used by boot partition and on reading them
> lots of warning are reported about wrong ECC data and if written to
> results in broken data and not bootable device.
> 
> The layout scheme used by these special page consist in using 512 bytes
> as the codeword size (even for the last codeword) while writing to CFG0
> register. This forces the NAND controller to unprotect the 4 bytes of
> spare data.
> 
> Since the kernel is unaware of this different layout for these special
> page, it does try to protect the spare data too during read/write and
> warn about CRC errors.
> 
> Add support for this by permitting the user to declare these special
> pages in dts by declaring offset and size of the partition. The driver
> internally will convert these value to nand pages.
> 
> On user read/write the page is checked and if it's a boot page the
> correct layout is used.
> 
> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next, thanks.

Miquel