Re: [PATCH] gpio: thunderx: select IRQ_DOMAIN_HIERARCHY instead of depends on

[David Daney]

On 09/05/2017 09:20 PM, Masahiro Yamada wrote:
> Hi David,
>
>
> 2017-09-06 11:09 GMT+09:00 David Daney <ddaney@xxxxxxxxxxxxxxxxxx>:
> > On 09/05/2017 06:40 PM, Masahiro Yamada wrote:
> > > IRQ_DOMAIN_HIERARCHY is not user-configurable, but supposed to be
> > > selected by drivers that need IRQ domain hierarchy support.
> > >
> > > GPIO_THUNDERX is the only user of "depends on IRQ_DOMAIN_HIERARCHY".
> > > This means, we can not enable GPIO_THUNDERX unless other drivers
> > > select IRQ_DOMAIN_HIERARCHY elsewhere.  This is odd.  Flip the logic.
> > >
> > > Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> >
> >
> > IRQ_DOMAIN_HIERARCHY is set as a result of ARCH_THUNDER (this SoC hardware),
> > so it actually works as-is.
>
>
> Right, ARCH_THUNDER does not select it directly,
> but does it indirectly.  (this is not so clear...)
>
> ARCH_THUNDER  -> ARM64 -> ARM_GIC -> IRQ_DOMAIN_HIERARCHY
>
>
>
> >   That said, this looks like a reasonable
> > improvement, and will allow the COMPILE_TEST to enable it, so...
> >
> > Acked-by: David Daney <david.daney@xxxxxxxxxx>
>
>
> BTW, I could not understand your intention of
> (64BIT && COMPILE_TEST)

The driver uses readq()/writeq(), which are not available in some 32BIT 
kernels.  So to ensure that it can build without error we depend on 
64BIT as a proxy for the availability of readq()/writeq()


David