Re: [PATCH v5 2/5] i2c: piix4: Depends on X86

[Mario Limonciello]

On 6/10/2025 2:24 AM, Huacai Chen wrote:
> On Tue, Jun 10, 2025 at 5:16 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> > Hi Mario,
> >
> > CC mips, loongarch
> >
> > On Wed, 23 Apr 2025 at 01:49, Mario Limonciello <superm1@xxxxxxxxxx> wrote:
> > > From: Mario Limonciello <mario.limonciello@xxxxxxx>
> > >
> > > PIIX4 and compatible controllers are only for X86. As some headers are
> > > being moved into x86 specific headers PIIX4 won't compile on non-x86.
> > >
> > > Suggested-by: Ingo Molnar <mingo@xxxxxxxxxx>
> > > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> >
> > Thanks for your patch, which is now commit 7e173eb82ae97175
> > ("i2c: piix4: Make CONFIG_I2C_PIIX4 dependent on CONFIG_X86")
> > in v6.16-rc1.
> >
> > > --- a/drivers/i2c/busses/Kconfig
> > > +++ b/drivers/i2c/busses/Kconfig
> > > @@ -200,7 +200,7 @@ config I2C_ISMT
> > >
> > >   config I2C_PIIX4
> > >          tristate "Intel PIIX4 and compatible (ATI/AMD/Serverworks/Broadcom/SMSC)"
> > > -       depends on PCI && HAS_IOPORT
> > > +       depends on PCI && HAS_IOPORT && X86
> >
> > Are you sure this south-bridge is not used on non-x86 platforms?
> > It is enabled in several non-x86 defconfigs:
> >
> >      arch/loongarch/configs/loongson3_defconfig:CONFIG_I2C_PIIX4=y
> >      arch/mips/configs/ip27_defconfig:CONFIG_I2C_PIIX4=m
> >      arch/mips/configs/loongson2k_defconfig:CONFIG_I2C_PIIX4=y
> >      arch/mips/configs/loongson3_defconfig:CONFIG_I2C_PIIX4=y
> >
> > The loongarch and loongson entries are probably bogus, but I wouldn't
> > be surprised if the SGI Onyx and Origin do use Intel south-bridges.
> Loongson can use AMD SB700/SB800 south bridges, which have I2C_PIIX4.

Well we could revert this patch, but it's going to be a compile failure 
because of 624b0d5696a89b138408d385899dd35372db324b and other patches 
that go on top of that.

My current leaning is we make a dummy fch.h header for these archs with 
#defines for 0.

Any thoughts?

> Huacai
>
> > >          select I2C_SMBUS
> > >          help
> > >            If you say yes to this option, support will be included for the Intel
> >
> > Gr{oetje,eeting}s,
> >
> >                          Geert
> >
> > --
> > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
> >
> > In personal conversations with technical people, I call myself a hacker. But
> > when I'm talking to journalists I just say "programmer" or something like that.
> >                                  -- Linus Torvalds