All of lore.kernel.org
 help / color / mirror / Atom feed
From: Viresh Kumar <viresh.kumar@linaro.org>
To: Saravana Kannan <saravanak@google.com>
Cc: Georgi Djakov <georgi.djakov@linaro.org>,
	Viresh Kumar <vireshk@kernel.org>, Nishanth Menon <nm@ti.com>,
	Stephen Boyd <sboyd@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Sibi Sankar <sibis@codeaurora.org>,
	Rajendra Nayak <rnayak@codeaurora.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Jordan Crouse <jcrouse@codeaurora.org>,
	Evan Green <evgreen@chromium.org>,
	Linux PM <linux-pm@vger.kernel.org>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
	<devicetree@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v7 6/7] OPP: Update the bandwidth on OPP frequency changes
Date: Mon, 4 May 2020 10:30:17 +0530	[thread overview]
Message-ID: <20200504050017.nsd7fp7gtxxwt3d7@vireshk-i7> (raw)
In-Reply-To: <CAGETcx-W5XjNtgjDz2Ma_miN=cUBb5LFfhzYtKRpf6iAi4bXNw@mail.gmail.com>

On 30-04-20, 09:32, Saravana Kannan wrote:
> You are missing the point. This is not about aggregation. This is
> about OPP voting for bandwidth on a path when the vote can/should be
> 0.
> 
> I'll give another example. Say one of the interconnect paths needs to
> be voted only when a particular use case is running. Say, the GPU
> needs to vote for bandwidth to L3 only when it's running in cache
> coherent mode. But it always needs to vote for bandwidth to DDR. With
> the way it's written now, OPP is going to force vote a non-zero
> bandwidth to L3 even when it can be zero. Wasting power for no good
> reason.
> 
> Just let the drivers/device get the bandwidth values from OPP without
> forcing them to vote for the bandwidth when they don't need to. Just
> because they decide to use OPP to set their clock doesn't mean they
> should lose to ability to control their bandwidth in a more
> intelligent fashion.

They shouldn't use opp_set_rate() in such a scenario. Why should they?

opp_set_rate() was introduced to take care of only the simple cases
and the complex ones are left for the drivers to handle. For example,
they take care of programming multiple regulators (in case of TI), as
OPP core can't know the order in which regulators need to be
programmed. But for the simple cases, opp core can program everything
the way it is presented in DT.

-- 
viresh

  reply	other threads:[~2020-05-04  5:00 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-24 15:53 [PATCH v7 0/7] Introduce OPP bandwidth bindings Georgi Djakov
2020-04-24 15:53 ` [PATCH v7 1/7] dt-bindings: opp: Introduce opp-peak-kBps and opp-avg-kBps bindings Georgi Djakov
2020-04-30  5:09   ` Viresh Kumar
2020-05-04 20:31   ` Sibi Sankar
2020-05-11 21:51   ` Rob Herring
2020-04-24 15:53 ` [PATCH v7 2/7] OPP: Add helpers for reading the binding properties Georgi Djakov
2020-04-24 17:30   ` Matthias Kaehlcke
2020-04-30  5:21     ` Viresh Kumar
2020-05-04 20:40   ` Sibi Sankar
2020-04-24 15:54 ` [PATCH v7 3/7] interconnect: Add of_icc_get_by_index() helper function Georgi Djakov
2020-04-24 18:02   ` Matthias Kaehlcke
2020-05-04 20:58   ` Sibi Sankar
2020-04-24 15:54 ` [PATCH v7 4/7] OPP: Add support for parsing interconnect bandwidth Georgi Djakov
2020-04-24 19:20   ` Matthias Kaehlcke
2020-04-28 16:21     ` Georgi Djakov
2020-04-30  5:28     ` Viresh Kumar
2020-05-04 21:03   ` Sibi Sankar
2020-04-24 15:54 ` [PATCH v7 5/7] OPP: Add sanity checks in _read_opp_key() Georgi Djakov
2020-04-24 19:26   ` Matthias Kaehlcke
2020-05-04 20:47   ` Sibi Sankar
2020-04-24 15:54 ` [PATCH v7 6/7] OPP: Update the bandwidth on OPP frequency changes Georgi Djakov
2020-04-24 19:36   ` Matthias Kaehlcke
2020-04-24 21:18   ` Saravana Kannan
2020-04-30  6:09     ` Viresh Kumar
2020-04-30  7:35       ` Saravana Kannan
2020-04-30  7:53         ` Viresh Kumar
2020-04-30 16:32           ` Saravana Kannan
2020-05-04  5:00             ` Viresh Kumar [this message]
2020-05-04 21:01               ` Saravana Kannan
2020-05-05  3:38                 ` Viresh Kumar
2020-05-04 20:54   ` Sibi Sankar
2020-04-24 15:54 ` [PATCH v7 7/7] cpufreq: dt: Add support for interconnect bandwidth scaling Georgi Djakov
2020-04-24 19:41   ` Matthias Kaehlcke
2020-05-04 20:50   ` Sibi Sankar

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200504050017.nsd7fp7gtxxwt3d7@vireshk-i7 \
    --to=viresh.kumar@linaro.org \
    --cc=bjorn.andersson@linaro.org \
    --cc=devicetree@vger.kernel.org \
    --cc=evgreen@chromium.org \
    --cc=georgi.djakov@linaro.org \
    --cc=jcrouse@codeaurora.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=nm@ti.com \
    --cc=rjw@rjwysocki.net \
    --cc=rnayak@codeaurora.org \
    --cc=robh+dt@kernel.org \
    --cc=saravanak@google.com \
    --cc=sboyd@kernel.org \
    --cc=sibis@codeaurora.org \
    --cc=vincent.guittot@linaro.org \
    --cc=vireshk@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.