linux-pm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ulf Hansson <ulf.hansson@linaro.org>
To: Stephan Gerhold <stephan@gerhold.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Kevin Hilman <khilman@kernel.org>, Nishanth Menon <nm@ti.com>,
	Stephen Boyd <sboyd@kernel.org>,
	Linux PM <linux-pm@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Niklas Cassel <nks@flawful.org>
Subject: Re: [RFC PATCH 0/3] opp: required_opps: Power on genpd, scale down in reverse order
Date: Wed, 12 Aug 2020 10:53:44 +0200	[thread overview]
Message-ID: <CAPDyKFqy5-qtfKy=8iyR+LZNUTVi8namLGk_juq4a9YZH8DVqg@mail.gmail.com> (raw)
In-Reply-To: <20200730080146.25185-1-stephan@gerhold.net>

On Thu, 30 Jul 2020 at 10:02, Stephan Gerhold <stephan@gerhold.net> wrote:
>
> I'm trying to get CPR (Core Power Reduction, AVS) working for MSM8916 on mainline.
> Shortly said there are two power domains that must be scaled with the CPU OPP table:
>
>   - (VDD)MX
>   - CPR
>
> My idea for this was to add both as "required-opps" to the CPR OPP table
> and let the OPP core take care of all the scaling.
>
> There are two remaining problems that need to be addressed for that to work:
>
>   1. The power domains should be scaled down in reverse order
>      (MX, CPR when scaling up, CPR, MX when scaling down).
>   2. Something has to enable the virtual genpd devices to make the rpmpd driver
>      actually respect the performance states we vote for.
>
> Both issues were briefly discussed before (see links in the patches),
> but I think we did not agree on an exact solution yet. After some consideration,
> I thought it would be best to address these directly in the OPP core.
>
> However, note that this patch is RFC because it is just supposed to initiate
> discussion if alternative solutions would be better. :)

Ramping up since the holidays, so I might overlook something - but I
think your suggestion solution makes perfect sense to me.

>
> Stephan Gerhold (3):
>   opp: Reduce code duplication in _set_required_opps()
>   opp: Set required OPPs in reverse order when scaling down
>   opp: Power on (virtual) power domains managed by the OPP core
>
>  drivers/opp/core.c | 115 ++++++++++++++++++++++++++++++++++++---------
>  drivers/opp/opp.h  |   1 +
>  2 files changed, 93 insertions(+), 23 deletions(-)
>
> --
> 2.27.0

So, for the series:

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe

      parent reply	other threads:[~2020-08-12  8:54 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-30  8:01 [RFC PATCH 0/3] opp: required_opps: Power on genpd, scale down in reverse order Stephan Gerhold
2020-07-30  8:01 ` [RFC PATCH 1/3] opp: Reduce code duplication in _set_required_opps() Stephan Gerhold
2020-08-24 11:18   ` Viresh Kumar
2020-08-24 11:30     ` Stephan Gerhold
2020-08-24 12:10       ` Viresh Kumar
2020-08-24 12:23         ` Stephan Gerhold
2020-07-30  8:01 ` [RFC PATCH 2/3] opp: Set required OPPs in reverse order when scaling down Stephan Gerhold
2020-08-21 16:31   ` Stephan Gerhold
2020-08-24 11:30     ` Viresh Kumar
2020-08-24 11:42       ` Stephan Gerhold
2020-07-30  8:01 ` [RFC PATCH 3/3] opp: Power on (virtual) power domains managed by the OPP core Stephan Gerhold
2020-08-24 11:27   ` Viresh Kumar
2020-08-24 11:55     ` Stephan Gerhold
2020-08-24 14:36       ` Ulf Hansson
2020-08-24 15:08         ` Stephan Gerhold
2020-08-25  4:43           ` Viresh Kumar
2020-08-25  6:43             ` Ulf Hansson
2020-08-25  7:33               ` Stephan Gerhold
2020-08-25 12:42                 ` Ulf Hansson
2020-08-26  8:31                   ` Stephan Gerhold
2020-08-12  8:53 ` Ulf Hansson [this message]

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='CAPDyKFqy5-qtfKy=8iyR+LZNUTVi8namLGk_juq4a9YZH8DVqg@mail.gmail.com' \
    --to=ulf.hansson@linaro.org \
    --cc=khilman@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=nks@flawful.org \
    --cc=nm@ti.com \
    --cc=rjw@rjwysocki.net \
    --cc=sboyd@kernel.org \
    --cc=stephan@gerhold.net \
    --cc=viresh.kumar@linaro.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).