On Tue, Nov 01, 2016 at 02:50:58PM +0100, Boris Brezillon wrote:
> On Fri, 28 Oct 2016 15:27:42 -0500
> Zach Brown <zach.br...@ni.com> wrote:
>
> > The fields bb_per_lun and blocks_per_lun are useful determining the
> > number of bad blocks a MTD needs to allocate. How they are set will
> > depend on if the chip is ONFI, JEDEC or a fuill-id entry in the nand_ids
> > table.
> >
> > Signed-off-by: Zach Brown <zach.br...@ni.com>
> > ---
> > include/linux/mtd/nand.h | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
> > index c5d3d502..efbe439 100644
> > --- a/include/linux/mtd/nand.h
> > +++ b/include/linux/mtd/nand.h
> > @@ -771,6 +771,9 @@ nand_get_sdr_timings(const struct nand_data_interface
> > *conf)
> > * supported, 0 otherwise.
> > * @jedec_params: [INTERN] holds the JEDEC parameter page when JEDEC is
> > * supported, 0 otherwise.
> > + * @bb_per_lun: [INTERN] the max number of bad blocks each LUN of a
> > + * this nand device will encounter their life times.
> > + * @blocks_per_lun: [INTERN] The number of PEBs in a LUN
> > * @read_retries: [INTERN] the number of read retry modes supported
> > * @onfi_set_features: [REPLACEABLE] set the features for ONFI nand
> > * @onfi_get_features: [REPLACEABLE] get the features for ONFI nand
> > @@ -853,6 +856,8 @@ struct nand_chip {
> > struct nand_onfi_params onfi_params;
> > struct nand_jedec_params jedec_params;
> > };
> > + __le16 bb_per_lun;
> > + __le32 blocks_per_lun;
>
> Two things I don't like here:
> - you use little-endian types, while it should use native endianness.
> Make it easier, and just declare those fields as int (or unsigned
> int).
> - you stick to the ONFI spec, while I'd prefer to see the term lun
> replaced by die, and I wonder if we don't already have a field
> storing the number of blocks per die (I might be wrong though).
>
I looked for an existing field for number of blocks per die and could not find
it. Perhaps you were remembering chipsize? or numchips? I looked at how they
were calculated and chipsize is a multiple of (blocks_per_lun * lun_count) so
it can't be used to find blocks_per_lun without storing lun_count anyways.
Let me know if you think I missed something.
