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

Paul Cercueil
2020-07-25T12:17:59Z

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:
>> > >
>> > > Hi Krzysztof,
>> > >
>> > >
>> > > Le ven. 24 juil. 2020 à 16:54, Krzysztof Kozlowski
>> > > <krzk@kernel.org> a
>> > > écrit :
>> > > > Enabling the MTD_NAND_JZ4780 driver makes sense only for
>> specific
>> > > > hardware - the Ingenic SoC architecture. Set it's
>> dependency to
>> > > > MACH_INGENIC so it will not appear on unrelated architectures
>> > > (easier
>> > > > job for downstream/distro kernel engineers).
>> > >
>> > > Disagreed. It was done this way so that distro kernels can
>> support
>> > > multiple SoCs.
>> >
>> > They will still be able to support multiple SoCs. Nothing changed
>> > here. The same we do for all ARM drivers (SoCs are
>> multiplatform)...
>> > Unless you want to say that it is possible to support Ingenic SoC
>> > without MACH_INGENIC?
>>
>> 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.

-Paul

>> I'm the one to blame for using "depends on
>> MIPS || COMPILE_TEST" on ingenic drivers, maybe it should depend on
>> MACH_INGENIC indeed, but then it should be made possible to support
>> more
>> than one SoC family.
>>
>> That's something that should be pointed out to the MIPS mailing
>> list, I
>> believe.
>
> Somehow JZ4780 entries in Maintainers do not mention MIPS list...
>
>>
>> Btw: Does that mean you are the new maintainer for drivers/memory/?
>
> Yes, that's the coming change.
>
> https://lore.kernel.org/lkml/20200724140345.GB13472@kozik-lap/T/#m91ca20920a7ec5f228a595f1816c15b6c85b6a09
>
> Best regards,
> Krzysztof
>