Re: [PATCH 01/44] mtd: add new API for handling MTD registration

[Jamie Iles <jamie@jamieiles.com>]

On Tue, Jun 07, 2011 at 07:48:58PM +0400, Dmitry Eremin-Solenikov wrote:
> Lots (nearly all) mtd drivers contain nearly the similar code that
> calls parse_mtd_partitions, provides some platform-default values, if
> parsing fails, and registers  mtd device.
> 
> This is an aim to provide single implementation of this scenario:
> mtd_device_parse_register() which will handle all this parsing and
> defaults.
> 
> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> ---
>  drivers/mtd/mtdcore.c   |   47 +++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/mtd/mtd.h |    5 +++++
>  2 files changed, 52 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index c510aff..d538e0a 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -452,6 +452,53 @@ int mtd_device_register(struct mtd_info *master,
>  EXPORT_SYMBOL_GPL(mtd_device_register);
>  
>  /**
> + * mtd_device_parse_register - register an MTD device.
> + *
> + * @mtd: the MTD device to register
> + * @part_probe_types: the list of MTD partition probes to try
> + * @origin: start address of MTD device. =0 unless you are sure you need this.
> + * @defparts: default partition information to register. Only valid if
> + *		defnr_parts > 0
> + * @defnr_parts: the number of partitions in defparts.  If zero then the full
> + *		MTD device is registered if no partition info is found
> + *
> + * Extract partition info and register MTD device (partitions or a whole device)
> + * It calls parse_mtd_partitions(), checks the result. If there were no
> + * partitions found, it uses default info specified (via defparts/defnr_parts)
> + * and then registers either partitions, or (if no partitions were
> + * found/specified) the whow MTD.

s/whow/whole ?

> + */
> +int mtd_device_parse_register(struct mtd_info *mtd,
> +			      const char **part_probe_types,
> +			      unsigned long origin,
> +			      const struct mtd_partition *defparts,
> +			      int defnr_parts)
> +{
> +	int err;
> +	struct mtd_partition *parts;
> +
> +	err = parse_mtd_partitions(mtd, part_probe_types, &parts, origin);
> +	if (err <= 0 && defnr_parts) {
> +		parts = kmemdup(defparts, sizeof(*parts) * defnr_parts,
> +				GFP_KERNEL);
> +		if (!parts)
> +			err = -ENOMEM;
> +	}

I see that some of your patches for drivers (e.g. plat_nand) remove the 
kfree() of the partitions but this doesn't appear to be handled anywhere 
else afaict.  I don't think this can be done in mtd_device_unregister() 
as it doesn't have the mtd_partition array so probably needs to remain 
in the driver.

Jamie