Re: [PATCH v4 0/3] Introduce Bandwidth OPPs for interconnects

From: Saravana Kannan <saravanak@google.com>
To: Sibi Sankar <sibis@codeaurora.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>,
	Georgi Djakov <georgi.djakov@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Viresh Kumar <vireshk@kernel.org>, Nishanth Menon <nm@ti.com>,
	Stephen Boyd <sboyd@kernel.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	"Sweeney, Sean" <seansw@qti.qualcomm.com>,
	David Dai <daidavid1@codeaurora.org>,
	adharmap@codeaurora.org, Rajendra Nayak <rnayak@codeaurora.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Evan Green <evgreen@chromium.org>,
	Android Kernel Team <kernel-team@android.com>,
	Linux PM <linux-pm@vger.kernel.org>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree@vger.kernel.org>, LKML <linux-kernel@vger.kerne>
Subject: Re: [PATCH v4 0/3] Introduce Bandwidth OPPs for interconnects
Date: Mon, 29 Jul 2019 22:53:12 -0700	[thread overview]
Message-ID: <CAGETcx_BpJswxA4AGARogZ1xRJPqm=_zTOZq1xJ2vgx+DUYsqQ@mail.gmail.com> (raw)
In-Reply-To: <361effba-4433-24d9-243c-201af39214cc@codeaurora.org>

On Mon, Jul 29, 2019 at 10:28 PM Sibi Sankar <sibis@codeaurora.org> wrote:
>
> Hey Viresh,
>
> On 7/30/19 8:16 AM, Viresh Kumar wrote:
> > On 29-07-19, 13:16, Saravana Kannan wrote:
> >> Sibi might be working on doing that for the SDM845 CPUfreq driver.
> >> Georgi could also change his GPU driver use case to use this BW OPP
> >> table and required-opps.
> >>
> >> The problem is that people don't want to start using this until we
> >> decide on the DT representation. So it's like a chicken and egg
> >> situation.
> >
> > Yeah, I agree to that.
> >
> > @Georgi and @Sibi: This is your chance to speak up about the proposal
> > from Saravana and if you find anything wrong with them. And specially
> > that it is mostly about interconnects here, I would like to have an
> > explicit Ack from Georgi on this.
> >
> > And if you guys are all okay about this then please at least commit
> > that you will convert your stuff based on this in coming days.
>
> I've been using both Saravana's and Georgi's series for a while
> now to scale DDR and L3 on SDM845. There is currently no consensus
> as to where the votes are to be actuated from, hence couldn't post
> anything out.
>
> DCVS based on Saravana's series + passive governor:
> https://github.com/QuinAsura/linux/tree/lnext-072619-SK-series

Thanks Sibi! You might want to convert your patches so that until the
passive governor is ready, you just look up the required opps and vote
for BW directly from the cpufreq driver. Once devfreq governor is
ready, you can switch to it.

-Saravana

>
> DCVS based on Georgi's series: (I had already posted this out)
> https://github.com/QuinAsura/linux/tree/lnext-072619-GJ-series
>
> --
> Qualcomm Innovation Center, Inc.
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