Messages in this thread | | | Date | Sat, 25 Oct 2014 11:55:27 +0800 | From | Huang Shijie <> | Subject | Re: [PATCH v4 1/4] mtd: nand: provide detailed description for raw read/write page methods |
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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.brezillon@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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