Re: [RFC PATCH 7/7] irqchip/apple-aic: add SMP support to the Apple AIC driver.

From: Mohamed Mediouni
Date: Thu Jan 21 2021 - 08:39:59 EST




> On 21 Jan 2021, at 14:22, Marc Zyngier <maz@xxxxxxxxxx> wrote:
>
> On 2021-01-21 12:50, Mohamed Mediouni wrote:
>>> On 21 Jan 2021, at 13:44, Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
>>> On Wed, Jan 20, 2021 at 2:27 PM Mohamed Mediouni
>
> [...]
>
>>>> + aic.fast_ipi = of_property_read_bool(node, "fast-ipi");
>>> Where is this property documented, and what decides which one to use?
>> It’s getting documented in the next patch set.
>> This property is there to enable support for older iPhone processors
>> later on, some of which do not have fast IPI support.
>> On Apple M1, fast-ipi is always on.
>
> Then please focus on a single implementation. Additional features can
> always be merged later once something is up and running.
>
> Also, there sysregs can be detected by matching the MIDR, so I don't
> think we need a DT property for that.
>
> Thanks,
>
Because UART access adapters for the new M1 Macs aren’t plentiful
at all, I actually use this for development, with iPhones which have
much more easy to buy Lightning-to-UART adapters.

(That’s why the old implementation is there too)

Might be worth splitting the new one to a new commit though...

Thank you,
> M.
> --
> Jazz is not dead. It just smells funny...