[PATCH 11/18] arm64: Kconfig: Require FIQ support for ARCH_APPLE

[Marc Zyngier]

On 2021-02-07 09:23, Hector Martin 'marcan' wrote:
> On 07/02/2021 00.46, Marc Zyngier wrote:
>>>   config ARCH_APPLE
>>>   	bool "Apple Silicon SoC family"
>>>   	select GENERIC_IRQ_CHIP
>>> +	select ARM64_FIQ_SUPPORT
>> 
>> Ah, this is what I was expecting in the previous patch. I guess the
>> initial ARCH_APPLE patch could be moved down the line and add all the
>> dependencies in one go.
> 
> I was trying to introduce the Kconfig before the code that depends on
> it; is it kosher to have it in the other order, looking for CONFIG_
> defines that don't exist yet?

Absolutely. The only requirement is to make sure that nothing breaks in
the middle of a series.

> Though in this case the only user earlier in the series is the Samsung
> stuff, which doesn't care about FIQs, so I can just sort things as
> FIQ->ARCH_APPLE->samsung->AIC...

Seems fine to me. Sorting out the infrastructure first (FIQ, memory
attributes) first is a requirement anyway, so the ordering of the
series could reflect that priority.

> I'm not sure about AIC vs. ARCH_APPLE though. Right now the pattern is
> that AIC depends on ARCH_APPLE and also defaults to that. But then you
> can build with ARCH_APPLE and AIC disabled if you so choose, which
> does result in a broken system on these machines. AIC should build
> without ARCH_APPLE (as long as we're on ARM64), so we could reverse
> that.

As long as ARCH_APPLE selects AIC, you can make AIC selectable on
its own. What I'm trying to avoid is people ending up with an unbootable
system, and not having interrupts is one thing that makes it really hard
to debug...

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...