[U-Boot] [PATCH 0/3] Add raw read support and use it in pxa3xx NAND driver

[Jagan Teki]

On Thu, Oct 11, 2018 at 9:16 PM Miquel Raynal <miquel.raynal at bootlin.com> wrote:
>
> When using 2kiB-pages NAND chips requesting an 8-bit strength ECC, the
> layout used is a bit particular and it happens that the ECC engine
> tries to correct uncorrectable errors on empty pages, producing
> bitflips.
>
> To avoid such situation, raw read support is added to the pxa3xx_nand
> driver, and then used to re-read the page (in raw mode) upon
> uncorrectable error detection to know if there is an actual ECC
> mismatch or if the page is empty. This way we avoid seeing the
> bitflips created by the hardware ECC engine.
>
> Once this done, we can revert the hack that was done in the driver to
> enlarge the last spare area for this layout to 64B instead of 32B,
> breaking U-Boot/Linux compatibility and preventing the BootROM to boot
> from NAND.
>
> Thanks,
> Miquèl
>
>
> Miquel Raynal (3):
>   mtd: nand: pxa3xx: add raw read support
>   mtd: nand: pxa3xx: re-read a page in raw mode on uncorrectable error
>   mtd: rawnand: pxa3xx: fix 2kiB pages with 8b strength chips layout

Acked-by: Jagan Teki <jagan at openedev.com>