Re: [PATCH] mtd: remove stale comment in mtd_oob_ops structure

[Boris Brezillon <boris.brezillon@bootlin.com>]

On Sat, 14 Jul 2018 14:32:34 +0200
Miquel Raynal <miquel.raynal@bootlin.com> wrote:

> A comment in the kernel doc of the mtd_oob_ops structure tells that it
> is not possible to write more than one page with OOB. This was
> probably true at some time in the past but today it is entirely wrong.
> 
> As one can see for instance in the nand_do_write_ops() helper available
> in the NAND core, this implementation called by mtd->_write_oob()
> simply loops over the pages until everything has been written.
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
>  include/linux/mtd/mtd.h | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
> index a86c4fa93115..59578aab277a 100644
> --- a/include/linux/mtd/mtd.h
> +++ b/include/linux/mtd/mtd.h
> @@ -66,10 +66,6 @@ struct mtd_erase_region_info {
>   *		mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
>   * @datbuf:	data buffer - if NULL only oob data are read/written
>   * @oobbuf:	oob data buffer
> - *
> - * Note, it is allowed to read more than one OOB area at one go, but not write.
> - * The interface assumes that the OOB write requests program only one page's
> - * OOB area.

Hm, I wouldn't be so prompt at nuking this comment since some
implementations (like onenand) really have this limitation. How about
adjusting the comment to reflect the fact that this limitation is
implementation dependent?

"
Note, some MTD drivers do not allow you to write more than one OOB area
at one go. If you try to do that on such an MTD device, -EINVAL will be
returned. If you want to make your implementation portable on all kind
of MTD devices you should split the write request into several
sub-requests when the request crosses a page boundary.
"

>   */
>  struct mtd_oob_ops {
>  	unsigned int	mode;