[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20221114065116.zs67pkbhhgfoze52@vireshk-i7>
Date: Mon, 14 Nov 2022 12:21:16 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: Hector Martin <marcan@...can.st>
Cc: "Rafael J. Wysocki" <rafael@...nel.org>,
Matthias Brugger <matthias.bgg@...il.com>,
Sven Peter <sven@...npeter.dev>,
Alyssa Rosenzweig <alyssa@...enzweig.io>,
Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Stephen Boyd <sboyd@...nel.org>,
Ulf Hansson <ulf.hansson@...aro.org>,
Marc Zyngier <maz@...nel.org>,
Mark Kettenis <mark.kettenis@...all.nl>, asahi@...ts.linux.dev,
linux-arm-kernel@...ts.infradead.org, linux-pm@...r.kernel.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 4/5] cpufreq: apple-soc: Add new driver to control
Apple SoC CPU P-states
On 09-11-22, 21:36, Hector Martin wrote:
> On 02/11/2022 15.18, Viresh Kumar wrote:
> >> + ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
> >
> > Why do you need this ? The OPP core should be able to find this
> > information by itself in your case AFAIU. The OPP core will refer
> > "operating-points-v2 = <&pcluster_opp>" and find that the cores are
> > related.
>
> We have multiple clusters sharing an OPP table (e.g. the M1 Ultra has 2
> e-cluster and 4 p-clusters, and duplicating OPP tables seems very
> silly), so this is necessary to tell it about the subset of cores
> sharing a table that are actually one domain.
The cluster sharing information is already part of the OPP tables, "opp-shared"
property. Platforms like scpi needed this because they didn't have the OPP table
in DT and so no way to find out the relation of the CPUs.
See how drivers/cpufreq/mediatek-cpufreq.c has done this.
dev_pm_opp_of_get_sharing_cpus() followed by dev_pm_opp_of_cpumask_add_table().
--
viresh
Powered by blists - more mailing lists