On Mon, 18 Jun 2018 22:41:03 +0200, Martin Kaiser <mar...@kaiser.cx>
wrote:
> The v21 version of the NAND flash controller contains a Spare Area Size
> Register (SPAS) at offset 0x10. Its setting defaults to the maximum
> spare area size of 218 bytes. The size that is set in this register is
> used by the controller when it calculates the ECC bytes internally in
> hardware.
>
> Usually, this register is updated from settings in the IIM fuses when
> the system is booting from NAND flash. For other boot media, however,
> the SPAS register remains at the default setting, which may not work for
> the particular flash chip on the board. The same goes for flash chips
> whose configuration cannot be set in the IIM fuses (e.g. chips with 2k
> sector size and 128 bytes spare area size can't be configured in the IIM
> fuses on imx25 systems).
>
> Set the SPAS register explicitly during the preset operation. Derive the
> register value from mtd->oobsize that was detected during probe by
> decoding the flash chip's ID bytes.
>
> While at it, rename the define for the spare area register's offset to
> NFC_V21_RSLTSPARE_AREA. The register at offset 0x10 on v1 controllers is
> different from the register on v21 controllers.
>
> Signed-off-by: Martin Kaiser <mar...@kaiser.cx>
> Cc: sta...@vger.kernel.org
> Fixes: d484018 ("mtd: mxc_nand: set NFC registers after reset")
Reviewed-by: Miquel Raynal <miquel.ray...@bootlin.com>
Thanks,
Miquèl
