Re: [PATCH v2 0/4] Apple SoC cpufreq driver

[Manivannan Sadhasivam]

Hi Viresh,

On Wed, May 04, 2022 at 03:57:45PM +0530, Viresh Kumar wrote:
> 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/
> 

Oops. Looks like that one slipped through the cracks. I did add it to my todo
list for qcom-cpufreq but missed it completely.

I will look into it.

Thanks,
Mani

> -- 
> viresh