On Mon, Oct 20, 2014 at 10:46:14AM +0200, Boris Brezillon wrote:
> read_page_raw and write_page_raw method description is not clear enough.
> It clearly specifies that ECC correction should not be involved but does
> not talk about specific layout (by layout I mean where in-band and
> out-of-band data are stored on the NAND media) used by NAND/ECC
> controllers.
>
> Those specific layouts might impact MTD users and thus should be hidden (as
> already done in the standard NAND_ECC_HW_SYNDROME implementation).
>
> Clearly state this constraint in the nand_ecc_ctrl struct documentation.
>
> Signed-off-by: Boris Brezillon <boris.brezil...@free-electrons.com>
> ---
> include/linux/mtd/nand.h | 17 +++++++++++++++--
> 1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
> index e4d451e..b14d190 100644
> --- a/include/linux/mtd/nand.h
> +++ b/include/linux/mtd/nand.h
> @@ -455,8 +455,21 @@ struct nand_hw_control {
> * be provided if an hardware ECC is available
> * @calculate: function for ECC calculation or readback from ECC
> hardware
> * @correct: function for ECC correction, matching to ECC generator (sw/hw)
> - * @read_page_raw: function to read a raw page without ECC
> - * @write_page_raw: function to write a raw page without ECC
> + * @read_page_raw: function to read a raw page without ECC. This function
> + * should hide the specific layout used by the ECC
> + * controller and always return contiguous in-band and
> + * out-of-band data even if they're not stored
> + * contiguously on the NAND chip (e.g.
> + * NAND_ECC_HW_SYNDROME interleaves in-band and
> + * out-of-band data).
> + * @write_page_raw: function to write a raw page without ECC. This function
> + * should hide the specific layout used by the ECC
> + * controller and consider the passed data as contiguous
> + * in-band and out-of-band data. ECC controller is
> + * responsible for doing the appropriate transformations
> + * to adapt to its specific layout (e.g.
> + * NAND_ECC_HW_SYNDROME interleaves in-band and
> + * out-of-band data).
> * @read_page: function to read a page according to the ECC generator
> * requirements; returns maximum number of bitflips corrected in
> * any single ECC step, 0 if bitflips uncorrectable, -EIO hw error
> --
> 1.9.1
>
thanks for this patch.
hi Brian, what's your opinion about this patch?
thanks
Huang Shijie
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