Re: [PATCH 1/2] mtd: move code adding master MTD out of mtd_add_device_partitions

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

On Fri, 12 Jan 2018 15:40:33 +0100
Rafał Miłecki <zajec5@gmail.com> wrote:

> From: Rafał Miłecki <rafal@milecki.pl>
> 
> This change is a small cleanup of mtd_device_parse_register. When using
> MTD_PARTITIONED_MASTER it makes sure a master MTD is registered before
> dealing with partitions. There are 2 advantages of this:
> 1) Not mixing code handling master MTD with code handling partitions
> 2) Possibility of reusing mtd_parse_part in the future to avoid some
>    code duplication.
> 
> This commit doesn't change any behavior except from a slightly different
> failure code path. The new code may need to call del_mtd_device when
> something goes wrong.
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> ---
>  drivers/mtd/mtdcore.c | 24 ++++++++++++------------
>  1 file changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index f80e911b8843..f6460862e2ad 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -641,20 +641,12 @@ static int mtd_add_device_partitions(struct mtd_info *mtd,
>  {
>  	const struct mtd_partition *real_parts = parts->parts;
>  	int nbparts = parts->nr_parts;
> -	int ret;
>  
> -	if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
> -		ret = add_mtd_device(mtd);
> -		if (ret)
> -			return ret;
> -	}
> +	if (nbparts == 0 && !IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
> +		return add_mtd_device(mtd);

Why not moving this part in mtd_device_parse_register() as well.

And I'd prefer something like:

	if (!nbparts && !device_is_registered(&mtd->dev))
		...

>  
> -	if (nbparts > 0) {
> -		ret = add_mtd_partitions(mtd, real_parts, nbparts);
> -		if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
> -			del_mtd_device(mtd);
> -		return ret;
> -	}
> +	if (nbparts > 0)
> +		return add_mtd_partitions(mtd, real_parts, nbparts);
>  
>  	return 0;
>  }
> @@ -714,6 +706,12 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
>  
>  	mtd_set_dev_defaults(mtd);
>  
> +	if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
> +		ret = add_mtd_device(mtd);
> +		if (ret)
> +			return ret;
> +	}
> +
>  	memset(&parsed, 0, sizeof(parsed));
>  
>  	ret = parse_mtd_partitions(mtd, types, &parsed, parser_data);
> @@ -753,6 +751,8 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
>  out:
>  	/* Cleanup any parsed partitions */
>  	mtd_part_parser_cleanup(&parsed);
> +	if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))

	if (ret && device_is_registered(&mtd->dev))

> +		del_mtd_device(mtd);

Blank line here, please.

>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(mtd_device_parse_register);