[PATCH] ARM: dts: rmobile: Drop MTD partitioning from DT

[marek.vasut@gmail.com (Marek Vasut)]

On 07/22/2018 12:01 AM, Olof Johansson wrote:
> On Sat, Jul 21, 2018 at 2:54 PM, Marek Vasut <marek.vasut@gmail.com> wrote:
>> On 07/21/2018 11:47 PM, Olof Johansson wrote:
>>> Hi,
>>
>> Hi,
>>
>>> On Wed, May 30, 2018 at 3:11 AM, Marek Vasut <marek.vasut@gmail.com> wrote:
>>>> Drop the MTD partitioning from DT, since it does not describe HW
>>>> and to give way to a more flexible kernel command line partition
>>>> passing.
>>>>
>>>> To retain the original partitioning, assure you have enabled
>>>> CONFIG_MTD_CMDLINE_PARTS in your kernel config and add the
>>>> following to your kernel command line:
>>>>
>>>> lager:   mtdparts=spi0.0:256k(loader),4m(user),-(flash)
>>>> stout:   mtdparts=spi0.0:512k(loader),256k(uboot),256k(uboot-env),-(flash)
>>>> koelsch: mtdparts=spi0.0:512k(loader),5632k(user),-(flash)
>>>> porter:  mtdparts=spi0.0:256k(loader_prg),4m(user_prg),-(flash_fs)
>>>> wheat:   mtdparts=spi0.0:256k(loader),4m(user),-(flash)
>>>> gose:    mtdparts=spi0.0:256k(loader),4m(user),-(flash)
>>>> alt:     mtdparts=spi0.0:256k(loader),256k(system),-(user)
>>>> silk:    mtdparts=spi0.0:256k(loader),4m(user),-(flash)
>>>
>>> Having to specify on command line is such a nasty hack. I wish we
>>> could remove that, and at the very least not add it for anything new.
>>
>> Do you have a better suggestion ?
> 
> Yes, keep it in DT.

See below

>>> You end up with user space tools trying to parse the kernel command
>>> line to figure out what's on the flash, and other really bad habits.
>>> :(
>>
>> You should just read /proc/mtd , see
>> http://www.linux-mtd.infradead.org/doc/general.html
> 
> Sure, I know that but not everybody does, and they do it in bad ways
> if given the opportunity.

That's what the documentation is for. I assume whoever is using MTD is
also capable of reading the documentation and thus avoiding such basic
mistakes.

>>> I'd strongly advice you to keep this in the board files, unless you
>>> have an actual real motivation for changing it. This patch does not
>>> provide one.
>>
>> Partitioning is not hardware description, it should not be in DT.
> 
> Read my reply again. It's part of _platform_ description, and belongs in DT.

I can repartition the flash whichever way I want for my purposes, just
like I can repartition a harddrive. We don't have harddrive partitioning
in the DT, why should we have flash partitioning there ? How do those
differ ?

-- 
Best regards,
Marek Vasut