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

[Krzysztof Kozlowski <krzk@kernel.org>]

On Mon, Dec 30, 2019 at 08:11:03PM +0100, Geert Uytterhoeven wrote:
> Hi Krzysztof,
> 
> On Mon, Dec 30, 2019 at 6:28 PM Krzysztof Kozlowski <krzk@kernel.org> 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@kernel.org>
> 
> Thanks for your patch!
> 
> > --- a/drivers/i2c/busses/Kconfig
> > +++ b/drivers/i2c/busses/Kconfig
> > @@ -367,7 +367,7 @@ comment "I2C system bus drivers (mostly embedded / system-on-chip)"
> >
> >  config I2C_ALTERA
> >         tristate "Altera Soft IP I2C"
> > -       depends on (ARCH_SOCFPGA || NIOS2) && OF
> > +       depends on (ARCH_SOCFPGA || NIOS2 || COMPILE_TEST) && OF
> 
> Might be easier to read and maintain by splitting in "hard" and "useful"
> dependencies:
> 
>     depends on OF
>     depends on ARCH_SOCFPGA || NIOS2 || COMPILE_TEST

Sure

> 
> > @@ -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.

> (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.

> 
> > @@ -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.

Best regards,
Krzysztof

> 
> > @@ -1403,8 +1405,8 @@ config I2C_OPAL
> >
> >  config I2C_ZX2967
> >         tristate "ZTE ZX2967 I2C support"
> > -       depends on ARCH_ZX
> > -       default y
> > +       depends on ARCH_ZX || (COMPILE_TEST && (ARC || ARM || ARM64 || M68K || RISCV || SUPERH || SPARC))
> 
> Same here/
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> -- 
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> 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