[PATCH v2 0/4] Apple SoC cpufreq driver

Viresh Kumar viresh.kumar at linaro.org
Wed May 4 03:27:45 PDT 2022


On 04-05-22, 16:51, Hector Martin wrote:
> Hi folks,
> 
> Here's a second take on the cpufreq driver for Apple SoCs. This is a
> complete rewrite using a stand-alone cpufreq driver instead of using the
> cpufreq-dt infrastructure.
> 
> Since v1 we ran some experiments on the memory controller performance
> switching and it turns out it doesn't make a huge difference, so it
> makes sense to punt that feature to the future (perhaps once a proper
> memory controller driver exists for other reasons, e.g. for error
> handling).
> 
> One advantage of having a standalone cpufreq driver is that we can
> support fast switching. This also means any future interaction with
> the memory controller will probably use some bespoke mechanism instead
> of the genpd infrastructure, so we can keep the fast path without
> allowing sleeps/etc.
> 
> The driver is based on scpi-cpufreq.c, with some bits (e.g. the
> apple,freq-domain stuff) inspired by how cpufreq-qcom-hw does it.
> I'm not sure if that particular property should be described
> in a binding, since it goes in the cpu nodes (qcom doesn't have it
> anywhere...).

Hi Mani,

I can see that Rob asked you to add this somewhere, maybe in arm/cpu
stuff, but I don't think you ever sent a patch with that. What
happened ?

https://lore.kernel.org/lkml/20201013171800.GA3716411@bogus/

-- 
viresh



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