Re: [PATCH V4 1/3] mtd: add new fields to nand_flash_dev{}

[Artem Bityutskiy <artem.bityutskiy@linux.intel.com>]

On Thu, 2013-03-07 at 18:49 +0800, Huang Shijie wrote:
> diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
> index 591eeeb..f0a9d93 100644
> --- a/include/linux/mtd/nand.h
> +++ b/include/linux/mtd/nand.h
> @@ -578,6 +578,8 @@ struct nand_chip {
>   * @erasesize: eraseblock size in bytes (determined from the extended ID if 0)
>   * @chipsize: total chip size in MiB
>   * @options: stores various chip bit options
> + * @id_len: The valid length of the @id.
> + * @oobsize: OOB size
>   */
>  struct nand_flash_dev {
>  	char *name;
> @@ -592,6 +594,8 @@ struct nand_flash_dev {
>  	unsigned long chipsize;
>  	unsigned long erasesize;
>  	unsigned long options;
> +	unsigned long id_len;
> +	unsigned long oobsize;
>  };

Why are these of type 'long', which is 64 bits in 64-bit architectures,
which seems to be unnecessarily big. Wouldn't 'unsigned int' be enough?

Also, can we avoid having the 'id_len' field? Can the end of the
sequence of ID's be marked with a '0' or '0xFF' marker instead?

-- 
Best Regards,
Artem Bityutskiy