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Subject: Re: [PATCH v6 1/2] PM / Domains: Add support for 'required-opps' to
 set default perf state
To:     Rajendra Nayak <rnayak@codeaurora.org>, ulf.hansson@linaro.org,
        bjorn.andersson@linaro.org, viresh.kumar@linaro.org
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From:   Dmitry Osipenko <digetx@gmail.com>
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Date:   Wed, 11 Aug 2021 22:48:24 +0300
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11.08.2021 12:45, Rajendra Nayak пишет:
>>
>> If you have more than one power domain, then this will override the
>> pstate which was set for a previous domain. This code doesn't feel solid
>> to me, at least a clarifying comment is needed about how it's supposed
>> to work.
> 
> I don't quite understand the concern here, this should work with devices
> having multiple power-domains as well. __genpd_dev_pm_attach gets called
> once per power-domain, and we use the index above to identify the
> power-domain.

The domain core code supports only one domain per device, see what
genpd_set_performance_state() does. This means that the second domain
will set the state of the *first* domain, which doesn't make sense. The
genpd_set_performance_state() will actually fail with -ENODEV for all
domains if you will try to do that.