Messages in this thread | | | From | Arnd Bergmann <> | Date | Thu, 21 Jan 2021 14:00:19 +0100 | Subject | Re: [RFC PATCH 7/7] irqchip/apple-aic: add SMP support to the Apple AIC driver. |
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On Thu, Jan 21, 2021 at 1:50 PM Mohamed Mediouni <mohamed.mediouni@caramail.com> wrote: > > On 21 Jan 2021, at 13:44, Arnd Bergmann <arnd@kernel.org> wrote: > >> @@ -186,8 +325,11 @@ static int __init apple_aic_init(struct device_node *node, > >> if (WARN(!aic.base, "unable to map aic registers\n")) > >> return -EINVAL; > >> > >> + 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.
Ok, makes sense. Does fast-ipi mean you cannot use the other mode at all, or is it just faster as implied by the name? If so, how much faster?
Arnd
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