Re: [PATCH v3 3/5] mtd: nand: Add bb_per_lun and blocks_per_lun fields to nand_chip

[Boris Brezillon <boris.brezillon@free-electrons.com>]

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).

>  
>  	struct nand_data_interface *data_interface;
>