Re: [PATCH v3 4/5] mtd_blkdevs: add option to enable scanning for partitions

[Miquel Raynal]

Hi Daniel,

daniel@xxxxxxxxxxxxxx wrote on Thu, 12 May 2022 20:39:27 +0100:

> Add Kconfig boolean CONFIG_MTD_BLOCK_PARTITIONS and enable block
> partition parsers on non-NAND mtdblock devices in case it is selected.
> 
> Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
> ---
>  drivers/mtd/Kconfig       | 11 +++++++++++
>  drivers/mtd/mtd_blkdevs.c |  4 +++-
>  2 files changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
> index 796a2eccbef0b8..12874dec15692a 100644
> --- a/drivers/mtd/Kconfig
> +++ b/drivers/mtd/Kconfig
> @@ -69,6 +69,17 @@ config MTD_BLOCK_RO
>  	  You do not need this option for use with the DiskOnChip devices. For
>  	  those, enable NFTL support (CONFIG_NFTL) instead.
>  
> +config MTD_BLOCK_PARTITIONS
> +	bool "Scan for partitions on MTD block devices"
> +	depends on MTD_BLOCK || MTD_BLOCK_RO
> +	default y if FIT_PARTITION
> +	help
> +	  Scan MTD block devices for partitions (ie. MBR, GPT, uImage.FIT, ...).
> +	  (NAND devices are omitted, ubiblock should be used instead when)
> +
> +	  Unless your MTD partitions contain sub-partitions mapped using a
> +	  partition table, say no.
> +
>  comment "Note that in some cases UBI block is preferred. See MTD_UBI_BLOCK."
>  	depends on MTD_BLOCK || MTD_BLOCK_RO
>  
> diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
> index f7317211146550..c67ce2e6fbeb0a 100644
> --- a/drivers/mtd/mtd_blkdevs.c
> +++ b/drivers/mtd/mtd_blkdevs.c
> @@ -359,7 +359,9 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
>  	} else {
>  		snprintf(gd->disk_name, sizeof(gd->disk_name),
>  			 "%s%d", tr->name, new->devnum);
> -		gd->flags |= GENHD_FL_NO_PART;
> +
> +		if (!IS_ENABLED(CONFIG_MTD_BLOCK_PARTITIONS) || mtd_type_is_nand(new->mtd))
> +			gd->flags |= GENHD_FL_NO_PART;

I really wonder if we need this in mtdblock ? Isn't ubiblock enough?

Anyhow,
Acked-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>

I'll let Richard ack the ubiblock patch.

Thanks,
Miquèl