Re: [PATCH 5/5] i2c: Enable compile testing for some of drivers

[Geert Uytterhoeven]

Hi Krzysztof,

On Tue, Dec 31, 2019 at 10:01 AM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
> On Mon, Dec 30, 2019 at 08:11:03PM +0100, Geert Uytterhoeven wrote:
> > On Mon, Dec 30, 2019 at 6:28 PM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
> > > Some of the I2C bus drivers can be compile tested to increase build
> > > coverage.  This requires also:
> > > 1. Adding dependencies on COMMON_CLK for BCM2835 and Meson I2C
> > >    controllers,
> > > 2. Adding 'if' conditional to 'default y' so they will not get enabled
> > >    by default on all other architectures,
> > > 3. Limiting few compile test options to supported architectures (which
> > >    provide the readsX()/writesX() primitives).
> > >
> > > Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>

> > > @@ -611,8 +612,8 @@ config I2C_EMEV2
> > >
> > >  config I2C_EXYNOS5
> > >         tristate "Exynos5 high-speed I2C driver"
> > > -       depends on ARCH_EXYNOS && OF
> > > -       default y
> > > +       depends on (ARCH_EXYNOS && OF) || COMPILE_TEST
> >
> > This means it is only useful on DT-based Exynos platforms, but compiles
> > everywhere?
>
> Yes. The driver will proble only from DT.
>
> >
> > Do you still have support for non-DT Exynos platforms?
> > ARCH_EXYNOS depends on ARCH_MULTI_V7?
>
> No, only DT. I think dependency here is a left over from board times and
> optional OF. Actually many drivers depend on OF and some OF-like ARCH so
> it could be removed.
>
> Since driver uses OF, it's rather the choice whether to explicitly
> mention OF.

So the !OF case is only for compile-testing.  Then it can be simplified to:

    depends on ARCH_EXYNOS || COMPILE_TEST

> > (and its help text mentions Exynos 4/5 only, no 3?)
>
> That's correct although it supports also Exynos7 (ARMv8) which is not
> mentioned. I'll correct it.

Good.

Actually "it" referred to arch/arm/mach-exynos/Kconfig:ARCH_EXYNOS,
which mentions 4/5 only, while it covers 3/4/5.

> > > @@ -1055,15 +1057,15 @@ config I2C_SYNQUACER
> > >
> > >  config I2C_TEGRA
> > >         tristate "NVIDIA Tegra internal I2C controller"
> > > -       depends on ARCH_TEGRA
> > > +       depends on ARCH_TEGRA || (COMPILE_TEST && (ARC || ARM || ARM64 || M68K || RISCV || SUPERH || SPARC))
> >
> > Perhaps
> >
> >     depends on ARCH_TEGRA || COMPILE_TEST
> >     depends on ARC || ARM || ARM64 || M68K || RISCV || SUPERH || SPARC
> > # needs <foo>
> >
> > to remember which <foo> feature is needed?
>
> I can comment on <foo> but such split of archs would be confusing. One
> would think that driver can work on these platforms, while it is purely
> for compile testing.  Keeping it together is self-documenting: these
> weird platform selection was added only for compile testing.

Fair enough.

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