u-boot and mtdparts

[Simon Glass]

Hi Marek,

On Thu, 15 Jul 2021 at 12:13, Marek Behún <marek.behun at nic.cz> wrote:
>
> Hello Tom and others,
>
> many boards still use the obsolete mtdparts command.
> What is the plan with this command? Do we still want to support it?
>
> Recently as discovered by Masami, my patch
>   mtd: spi-nor: allow  registering multiple MTDs when DM is enabled
> caused that mtds may have different name than that defined in
> CONFIG_MTDPARTS_DEFAULT.
> Masami fixed his board by putting the partition definitions into
> devicetree, but there are still many boards that may be broken.
>
> The easy fix here is to make mtd_device_matches_name() in
> drivers/mtd/mtdcore.c to support the old names. Most of them are in
> format "type.id", for example "nor.1", "nand.1", but some are different.
>
> The problem is that I do not know how exactly to match these names with
> the devices. Does the number represent the bus, or chip select or
> something else?
>
> There are also multiple parsers of the mtdparts string (at least two,
> one in cmd/mtdparts.c and the other in drivers/mtd/mtd_uboot.c).
>
> IMO the proper solution would be to get rid of the mtdparts entirely,
> move it to devicetree, and add code that generates the mtdparts string
> for Linux' command line from devicetree.
>
> What do you think?

SGTM. Let's add some tests too.

Regards,
Simon