linux-kernel - Re: [PATCH v1] PM: domains: Improve runtime PM performance state handling

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Message-ID: <CAJZ5v0hox4Y7pQARTTjMkj5TdDkcuKkyeB3=YR3YFnAcGMUJeA@mail.gmail.com>
Date:   Wed, 25 Aug 2021 20:17:27 +0200
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Ulf Hansson <ulf.hansson@...aro.org>
Cc:     Dmitry Osipenko <digetx@...il.com>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Kevin Hilman <khilman@...nel.org>,
        Viresh Kumar <vireshk@...nel.org>,
        Stephen Boyd <sboyd@...nel.org>, Nishanth Menon <nm@...com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-tegra <linux-tegra@...r.kernel.org>,
        Linux PM <linux-pm@...r.kernel.org>
Subject: Re: [PATCH v1] PM: domains: Improve runtime PM performance state handling

On Tue, Aug 24, 2021 at 9:51 AM Ulf Hansson <ulf.hansson@...aro.org> wrote:
>
> On Mon, 23 Aug 2021 at 22:25, Dmitry Osipenko <digetx@...il.com> wrote:
> >
> > GENPD core doesn't support handling performance state changes while
> > consumer device is runtime-suspended or when runtime PM is disabled.
> > GENPD core may override performance state that was configured by device
> > driver while RPM of the device was disabled or device was RPM-suspended.
> > Let's close that gap by allowing drivers to control performance state
> > while RPM of a consumer device is disabled and to set up performance
> > state of RPM-suspended device that will be applied by GENPD core on
> > RPM-resume of the device.
> >
> > Fixes: 5937c3ce2122 ("PM: domains: Drop/restore performance state votes for devices at runtime PM")
> > Signed-off-by: Dmitry Osipenko <digetx@...il.com>
>
> Reviewed-by: Ulf Hansson <ulf.hansson@...aro.org>
>
> Rafael, if not too late, can you please queue this as a fix for v5.14?
> I haven't heard about any regression, but the error is there.

Done, thanks!


> > ---
> >  drivers/base/power/domain.c | 10 ++++++++--
> >  1 file changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> > index e1c8994ae225..3a13a942d012 100644
> > --- a/drivers/base/power/domain.c
> > +++ b/drivers/base/power/domain.c
> > @@ -435,7 +435,7 @@ static void genpd_restore_performance_state(struct device *dev,
> >  int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state)
> >  {
> >         struct generic_pm_domain *genpd;
> > -       int ret;
> > +       int ret = 0;
> >
> >         genpd = dev_to_genpd_safe(dev);
> >         if (!genpd)
> > @@ -446,7 +446,13 @@ int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state)
> >                 return -EINVAL;
> >
> >         genpd_lock(genpd);
> > -       ret = genpd_set_performance_state(dev, state);
> > +       if (pm_runtime_suspended(dev)) {
> > +               dev_gpd_data(dev)->rpm_pstate = state;
> > +       } else {
> > +               ret = genpd_set_performance_state(dev, state);
> > +               if (!ret)
> > +                       dev_gpd_data(dev)->rpm_pstate = 0;
> > +       }
> >         genpd_unlock(genpd);
> >
> >         return ret;
> > --
> > 2.32.0
> >