[PATCH v1] dfu: fix dev_part_str for file operations

[Mattijs Korpershoek]

Hi Ivan,

Thank you for the patch, nice catch!

On Wed, Jun 11, 2025 at 05:00, Ivan Pang <ipman at amazon.com> wrote:

> The third_arg for a dfu alt is read as an integer and is overloaded for
> different supported backends. For ext4 and fat, this third_arg
> represents the partition and forms the dev part string, which should
> have its partition in hex. This commit fixes dfu ext4/fat usage for
> devices with ten or more partitions.
>
> Signed-off-by: Ivan Pang <ipman at amazon.com>

Reviewed-by: Mattijs Korpershoek <mkorpershoek at kernel.org>

> ---
>
>  drivers/dfu/dfu_mmc.c  | 2 +-
>  drivers/dfu/dfu_scsi.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dfu/dfu_mmc.c b/drivers/dfu/dfu_mmc.c
> index c19eb919388..a91671755e1 100644
> --- a/drivers/dfu/dfu_mmc.c
> +++ b/drivers/dfu/dfu_mmc.c
> @@ -117,7 +117,7 @@ static int mmc_file_op(enum dfu_op op, struct dfu_entity *dfu,
>  		return -1;
>  	}
>  
> -	snprintf(dev_part_str, sizeof(dev_part_str), "%d:%d",
> +	snprintf(dev_part_str, sizeof(dev_part_str), "%d:%x",
>  		 dfu->data.mmc.dev, dfu->data.mmc.part);
>  
>  	ret = fs_set_blk_dev("mmc", dev_part_str, fstype);
> diff --git a/drivers/dfu/dfu_scsi.c b/drivers/dfu/dfu_scsi.c
> index 9f95194784c..7ec34a8f7e3 100644
> --- a/drivers/dfu/dfu_scsi.c
> +++ b/drivers/dfu/dfu_scsi.c
> @@ -96,7 +96,7 @@ static int scsi_file_op(enum dfu_op op, struct dfu_entity *dfu, u64 offset, void
>  		return -1;
>  	}
>  
> -	snprintf(dev_part_str, sizeof(dev_part_str), "%d:%d", dfu->data.scsi.dev,
> +	snprintf(dev_part_str, sizeof(dev_part_str), "%d:%x", dfu->data.scsi.dev,
>  		 dfu->data.scsi.part);
>  
>  	ret = fs_set_blk_dev("scsi", dev_part_str, fstype);
> -- 
> 2.47.1