Messages in this thread | | | Date | Mon, 14 Nov 2022 12:21:16 +0530 | From | Viresh Kumar <> | Subject | Re: [PATCH v3 4/5] cpufreq: apple-soc: Add new driver to control Apple SoC CPU P-states |
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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
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