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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Wed, 26 Oct 2022 13:31:05 +0200
Message-ID: <CAJZ5v0hJxRiL03XDFpU8FuabsHn5i6JMksJ=dfj8B+Dm=s3LYA@mail.gmail.com>
Subject: Re: [PATCH] PM: domains: Fix handling of unavailable/disabled idle states
To:     Ulf Hansson <ulf.hansson@linaro.org>,
        Sudeep Holla <sudeep.holla@arm.com>
Cc:     Amit Pundir <amit.pundir@linaro.org>, linux-pm@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Bjorn Andersson <andersson@kernel.org>,
        Andy Gross <agross@kernel.org>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
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On Tue, Oct 25, 2022 at 2:59 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> On Tue, 25 Oct 2022 at 14:34, Sudeep Holla <sudeep.holla@arm.com> wrote:
> >
> > Platforms can provide the information about the availability of each
> > idle states via status flag. Platforms may have to disable one or more
> > idle states for various reasons like broken firmware or other unmet
> > dependencies.
> >
> > Fix handling of such unavailable/disabled idle states by ignoring them
> > while parsing the states.
> >
> > Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> > Cc: Ulf Hansson <ulf.hansson@linaro.org>
> > Fixes: a3381e3a65cb ("PM / domains: Fix up domain-idle-states OF parsing")
> > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
>
> I think this should be tagged for stable kernels too. Rafael, can you
> pick this up as a fix for v6.1rc[n]?
>
> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Applied as 6.1-rc material, thanks!

>
> > ---
> >  drivers/base/power/domain.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > Hi Ulf,
> >
> > As you already know, this change alone doesn't fix the issue reported here[1].
> > It also needs the fixes you have posted [2].
> >
> > Regards,
> > Sudeep
> >
> > [1] https://lore.kernel.org/all/20221018145348.4051809-1-amit.pundir@linaro.org
> > [2] https://lore.kernel.org/all/20221021151013.148457-1-ulf.hansson@linaro.org
>
> Well, I think it's better if we replace [1] with a patch that only
> disables the cluster idle state. In that case, it would be sufficient
> with $subject patch. In that case, we can just manage [2] separately.
>
> Amit, can you submit a new version and test it together with $subject patch?
>
> Kind regards
> Uffe
>
> >
> > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> > index ead135c7044c..6471b559230e 100644
> > --- a/drivers/base/power/domain.c
> > +++ b/drivers/base/power/domain.c
> > @@ -2952,6 +2952,10 @@ static int genpd_iterate_idle_states(struct device_node *dn,
> >                 np = it.node;
> >                 if (!of_match_node(idle_state_match, np))
> >                         continue;
> > +
> > +               if (!of_device_is_available(np))
> > +                       continue;
> > +
> >                 if (states) {
> >                         ret = genpd_parse_state(&states[i], np);
> >                         if (ret) {
> > --
> > 2.38.1
> >