lkml.org 
[lkml]   [2016]   [Nov]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v3 3/5] mtd: nand: Add bb_per_lun and blocks_per_lun fields to nand_chip
    On Tue, 1 Nov 2016 13:32:32 -0500
    Zach Brown <zach.brown@ni.com> wrote:

    > 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.brown@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.brown@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.

    Probably not, we so many fields in the nand_chip and mtd_info struct
    that I don't remember which ones we are missing ;-).

    \
     
     \ /
      Last update: 2016-11-06 18:53    [W:2.407 / U:0.644 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site