Re: [PATCH v8 2/3] mtd: nand: raw: qcom_nandc: add support for unprotected spare data pages

[Miquel Raynal]

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@xxxxxxxxx>
> Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>

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

Miquel