From: Ulf Hansson <ulf.hansson@linaro.org>
To: swboyd@chromium.org, Rajendra Nayak <rnayak@codeaurora.org>
Cc: Andy Gross <andy.gross@linaro.org>, Rob Herring <robh@kernel.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
David Collins <collinsd@codeaurora.org>,
Matthias Kaehlcke <mka@chromium.org>,
DTML <devicetree@vger.kernel.org>,
linux-arm-msm <linux-arm-msm@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v6 10/10] soc: qcom: rpmhpd: Mark mx as a parent for cx
Date: Thu, 13 Dec 2018 17:02:43 +0100 [thread overview]
Message-ID: <CAPDyKFrY_9qHq_3NGHpOxCLRDV-D4RiaKm_Wckqxa5ukHcEt+Q@mail.gmail.com> (raw)
In-Reply-To: <154463956571.17204.13154447854211552369@swboyd.mtv.corp.google.com>
On Wed, 12 Dec 2018 at 19:32, Stephen Boyd <swboyd@chromium.org> wrote:
>
> Quoting Rajendra Nayak (2018-12-11 20:13:13)
> >
> > >>> Just to make sure there are no conflicting hierarchical constraints
> > >>> between idle management and performance state management!?
> > >>>
> > >
> > > I'm not sure what idle states mean to the CX and MX domains. Would it be
> > > some sort of idle state governor attached at genpd creation time that
> > > would adjust the main SoC power rails when all devices attached are
> > > idle? Maybe I don't understand how idle states are different from
> > > performance states.
> > > My understanding is that devices using these domains would almost always
> > > expect their clk frequency and clk on/off state to decide what the
> > > performance state is, unless they need to ignore clk state because they
> > > aren't managing clks and bump up the voltage directly when the device is
> > > active. Either way, devices are actively managing the voltage they need
> > > these voltage domains to operate at by using the genpd performance
> > > states APIs.
> >
> > I am not quite sure whats the point that you are trying to make here,
> > but this is what I would expect the users of these genpds to do,
> > regardless of if they have a clk dependency or not.
> > When the device is active, vote for a performance state they need
> > then request for the genpd to be on. When they are idle, request for the
> > genpd to be turned off.
> >
>
> I believe Ulf is asking because he's proposing to make genpd idle states
> and genpd performance states orthogonal to each other. And to also make
> performance states unaffected by the on/off state of the genpd.
Yes, that's one of the reasons.
Anyway, I appreciate both of yours descriptive feedback, no further
worries from my side!
Kind regards
Uffe
next prev parent reply other threads:[~2018-12-13 16:03 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-11 9:49 [PATCH v6 00/10] Add power domain driver for corners on msm8996/sdm845 Rajendra Nayak
2018-12-11 9:49 ` [PATCH v6 01/10] dt-bindings: opp: Introduce qcom-opp bindings Rajendra Nayak
2018-12-11 9:49 ` [PATCH v6 02/10] dt-bindings: power: Add qcom rpm power domain driver bindings Rajendra Nayak
2018-12-11 21:28 ` Stephen Boyd
2018-12-11 9:49 ` [PATCH v6 03/10] soc: qcom: rpmpd: Add a Power domain driver to model corners Rajendra Nayak
2018-12-11 21:52 ` Stephen Boyd
2018-12-11 9:49 ` [PATCH v6 04/10] soc: qcom: rpmpd: Add support for get/set performance state Rajendra Nayak
2018-12-11 9:49 ` [PATCH v6 05/10] arm64: dts: msm8996: Add rpmpd device node Rajendra Nayak
2018-12-11 21:53 ` Stephen Boyd
2018-12-11 9:49 ` [PATCH v6 06/10] soc: qcom: rpmhpd: Add RPMh power domain driver Rajendra Nayak
2018-12-11 22:01 ` Stephen Boyd
2018-12-12 5:04 ` Rajendra Nayak
2018-12-11 9:49 ` [PATCH v6 07/10] arm64: dts: sdm845: Add rpmh powercontroller node Rajendra Nayak
2018-12-11 22:01 ` Stephen Boyd
2018-12-11 9:49 ` [PATCH v6 08/10] PM / Domains: Add a simple_opp_to_performance_state() helper Rajendra Nayak
2018-12-11 21:33 ` Stephen Boyd
2018-12-11 9:49 ` [PATCH v6 09/10] soc: qcom: rpmpd: Use " Rajendra Nayak
2018-12-11 21:34 ` Stephen Boyd
2018-12-11 9:49 ` [PATCH v6 10/10] soc: qcom: rpmhpd: Mark mx as a parent for cx Rajendra Nayak
2018-12-11 10:22 ` Ulf Hansson
2018-12-11 10:33 ` Rajendra Nayak
2018-12-11 21:50 ` Stephen Boyd
2018-12-12 4:13 ` Rajendra Nayak
2018-12-12 18:32 ` Stephen Boyd
2018-12-13 16:02 ` Ulf Hansson [this message]
2018-12-11 21:51 ` [PATCH v6 00/10] Add power domain driver for corners on msm8996/sdm845 Stephen Boyd
2018-12-12 4:17 ` Rajendra Nayak
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