Messages in this thread | | | Date | Thu, 21 Jan 2021 13:32:35 +0000 | From | Mark Rutland <> | 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 01:22:37PM +0000, Marc Zyngier wrote: > On 2021-01-21 12:50, Mohamed Mediouni wrote: > > > On 21 Jan 2021, at 13:44, Arnd Bergmann <arnd@kernel.org> 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.
Generally we do not detect IMP-DEF sysregs based on MIDR because they won't necessarily be exposed to a VM, so I suspect that we do need DT properties to describe that IMP-DEF sysregs are accessible, and should not rely on the MIDR alone. Maybe that's implicit in another property, but worth bearing in mind.
Thanks, Mark.
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