Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property

From	Viresh Kumar <viresh.kumar@linaro.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property
Date	2017-05-08 09:20 +0200
Message-ID	<tEL7z-P9-3@gated-at.bofh.it> (permalink)
References	(1 earlier) <tAsPV-197-35@gated-at.bofh.it> <tBkZY-4ij-13@gated-at.bofh.it> <tEfKp-4Y7-1@gated-at.bofh.it> <tEIjn-7gc-1@gated-at.bofh.it> <tEJyN-80c-7@gated-at.bofh.it>
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I had a long chat with Rajendra offline and clarified few things..

On 08-05-17, 11:06, Rajendra Nayak wrote:
> On 05/08/2017 09:45 AM, Viresh Kumar wrote:
> > On 06-05-17, 11:58, Kevin Hilman wrote:

> >> I had the same question.  Seems the same comment about an abstract
> >> "index" is needed for voltage also.
> > 
> > Why should we do that? Here are the cases that I had in mind while writing this:
> > 
> > - DT only contains the performance-index and nothing else (i.e. voltages aren't
> >   exposed).
> > 
> >   We wouldn't be required to fill the microvolt property as it is optional.
> 
> So the performance-index is specified in opp-hz property?

Yes, but in the OPP table of the power-domain and not the device. The
device can still have its own OPP table with normal freq/voltage
values (for a separate regulator).

> What if the microcontroller firmware maps the performance-index to voltage but
> expects linux to scale the frequency?

As you clarified on the chat, you were talking about the device here.
It isn't a problem as we will have two separate tables here, one for
the device and one for the domain.

-- 
viresh

Thread

[PATCH V6 0/9] PM / Domains: Implement domain performance states Viresh Kumar <viresh.kumar@linaro.org> - 2017-04-26 13:00 +0200
  [PATCH V6 8/9] PM / Domain: Add struct device to genpd Viresh Kumar <viresh.kumar@linaro.org> - 2017-04-26 13:00 +0200
  [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Viresh Kumar <viresh.kumar@linaro.org> - 2017-04-26 13:00 +0200
    Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Rob Herring <robh@kernel.org> - 2017-04-28 22:50 +0200
      Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Sudeep Holla <sudeep.holla@arm.com> - 2017-05-03 13:40 +0200
        Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Kevin Hilman <khilman@baylibre.com> - 2017-05-06 23:50 +0200
          Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Sudeep Holla <sudeep.holla@arm.com> - 2017-05-08 15:50 +0200
        Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Viresh Kumar <viresh.kumar@linaro.org> - 2017-05-08 09:20 +0200
          Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Sudeep Holla <sudeep.holla@arm.com> - 2017-05-08 16:00 +0200
            Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Viresh Kumar <viresh.kumar@linaro.org> - 2017-05-09 07:30 +0200
      Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Kevin Hilman <khilman@baylibre.com> - 2017-05-06 23:50 +0200
        Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Viresh Kumar <viresh.kumar@linaro.org> - 2017-05-08 06:20 +0200
          Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Rajendra Nayak <rnayak@codeaurora.org> - 2017-05-08 07:40 +0200
            Re: [PATCH V6 1/9] PM / OPP: Introduce "power-domain-opp" property Viresh Kumar <viresh.kumar@linaro.org> - 2017-05-08 09:20 +0200
  [PATCH V6 7/9] PM / domain: Register PM QOS performance notifier Viresh Kumar <viresh.kumar@linaro.org> - 2017-04-26 13:00 +0200
  [PATCH V6 5/9] PM / OPP: Add support to parse "power-domain-opp" property Viresh Kumar <viresh.kumar@linaro.org> - 2017-04-26 13:00 +0200

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