Re: [PATCH v3 2/2] mtd: rawnand: ingenic: Limit MTD_NAND_JZ4780 to architecture only

Krzysztof Kozlowski
2020-07-26T16:15:57Z

On Sun, Jul 26, 2020 at 06:12:27PM +0200, Paul Cercueil wrote:
>
>
> Le dim. 26 juil. 2020 à 18:06, Krzysztof Kozlowski <krzk@kernel.org> a écrit
> :
> > On Sat, Jul 25, 2020 at 08:30:56PM +0200, Arnd Bergmann wrote:
> > > On Sat, Jul 25, 2020 at 2:17 PM Paul Cercueil
> > > <paul@crapouillou.net> wrote:
> > > > Le ven. 24 juil. 2020 à 17:54, Krzysztof Kozlowski
> > > <krzk@kernel.org> a
> > > > écrit :
> > > > > On Fri, Jul 24, 2020 at 05:50:06PM +0200, Paul Cercueil wrote:
> > > > >> Le ven. 24 juil. 2020 à 17:33, Krzysztof Kozlowski
> > > > >> <krzk@kernel.org> a écrit:
> > > > >> > On Fri, 24 Jul 2020 at 17:19, Paul Cercueil
> > > <paul@crapouillou.net>
> > > > >> > wrote:
> > > > >>
> > > > >> On MIPS, the SoC selection is a Kconfig "choice", so you can
> > > only
> > > > >> support
> > > > >> one SoC family, unfortunately.
> > > > >
> > > > > Let's say someone selected then some other architecture
> > > > > (MIPS_ALCHEMY).
> > > > > They could select this MTD driver.
> > > > >
> > > > > Does it mean they would be able to run it on Ingenic hardware?
> > > >
> > > > In *theory* yes, as long as the Kconfig options that MACH_INGENIC
> > > > selects are enabled, the kernel should boot and work on Ingenic
> > > SoCs.
> > >
> > > Right now, this won't work yet, because there are platform specific
> > > functions that are implemented by each of the platforms in
> > > arch/mips,
> > > e.g. arch/mips/generic/init.c and arch/mips/jz4740/setup.c.
> >
> > I would say even more - no DTS would be provided for such configuration.
> > All Ingenic DTSes are included only with MACH_INGENIC. You cannot build
> > a kernel working on Ingenic without MACH_INGENIC. Even in theory.
>
> But the devicetree doesn't have to be built-in.
>

OK, that's true. Anyway, I don't have strong opinion on any of this. I
just followed Arnd's hint.

For the memory driver (and MTD NAND as well) which one you prefer:
1. https://lore.kernel.org/lkml/20200724074038.5597-6-krzk@kernel.org/
2. depends on MACH_INGENIC || MIPS_GENERIC || COMPILE_TEST

?

Best regards,
Krzysztof