Re: [RESEND PATCH v2 3/7] PM: domains: Add support for runtime PM

[Ulf Hansson]

On Fri, 9 Jul 2021 at 13:39, Dmitry Baryshkov
<dmitry.baryshkov@xxxxxxxxxx> wrote:
>
> Hi,
>
> On Fri, 9 Jul 2021 at 11:25, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> >
> > On Fri, 9 Jul 2021 at 06:32, Dmitry Baryshkov
> > <dmitry.baryshkov@xxxxxxxxxx> wrote:
> > >
> > > Registers for some genpds can be located in the SoC area, powered up by
> > > another power domain. To enabled access to those registers, respective
> > > domain should be turned on.
> > >
> > > This patch adds basic infrastructure to the genpd code to allow
> > > implementing drivers for such genpd. PM domain can provide the parent
> > > device through the genpd->dev.parent pointer. If its provided at the
> > > pm_genpd_init() call time and if it is pm-enabled, genpd power_on and
> > > power_off operations will call pm_runtime_get_sync() before powering up
> > > the domain and pm_runtime_put_sync() after powering it down.
> > >
> > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> >
> > Hi Dmitry,
> >
> > Using runtime PM for the genpd provider device, is not the correct
> > approach. If the provider domain needs another domain to be powered on
> > to work correctly, that per definition means that it has a parent
> > domain.
> >
> > I suggest you try to build the correct PM domain topology, via using
> > pm_genpd_add_subdomain() or of_genpd_add_subdomain(), then genpd will
> > manages the power on/off for parent/child domain internally.
>
> Indeed, this patch seems redundant now, with the
> pm_genpd_add_subdomain call in place.
> Would you like me to resend a v3 just dropping this patch?

Yes, $subject patch isn't the way to go.

Let's continue discussing things on patch3/7 to conclude on the way forward.

[...]

Kind regards
Uffe