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

From: David Daney
Date: Wed Sep 06 2017 - 13:36:19 EST


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