linux-kernel - Re: [PATCH v12 1/4] PM / Domains: Add a generic data pointer to the genpd_power

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Message-ID: <a750f654-3bc0-f102-245f-fbc8abb08298@linaro.org>
Date:   Thu, 21 Mar 2019 10:52:53 +0100
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     Ulf Hansson <ulf.hansson@...aro.org>
Cc:     "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Linux PM <linux-pm@...r.kernel.org>,
        Frederic Weisbecker <fweisbec@...il.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Sudeep Holla <sudeep.holla@....com>,
        Lorenzo Pieralisi <Lorenzo.Pieralisi@....com>,
        Mark Rutland <mark.rutland@....com>,
        "Raju P . L . S . S . S . N" <rplsssn@...eaurora.org>,
        Stephen Boyd <sboyd@...nel.org>,
        Tony Lindgren <tony@...mide.com>,
        Kevin Hilman <khilman@...nel.org>,
        Lina Iyer <ilina@...eaurora.org>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        linux-arm-msm <linux-arm-msm@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v12 1/4] PM / Domains: Add a generic data pointer to the
 genpd_power_state struct

On 21/03/2019 10:36, Ulf Hansson wrote:
> On Thu, 21 Mar 2019 at 08:47, Daniel Lezcano <daniel.lezcano@...aro.org> wrote:

[ ... ]

>>>       cancel_work_sync(&genpd->power_off_work);
>>> -     kfree(genpd->free);
>>> +     if (genpd->free_states)
>>
>> Is this test necessary as the free_states function is initialized with
>> the genpd_set_default_power_state() in any case?
> 
> That's the case when the genpd provider did not allocate states, so
> then we know genpd deals with this properly for us.
> 
> In the other case, when genpd provider has allocates states, then we
> need to check that the provider has assigned the ->free_states()
> callback before we invokes it, as there is no guarantees that it had.
> 
> I was initially tempted to do this check already at pm_genpd_init(),
> as it would allow us to check for the error condition and return an
> error code if it's not been assigned. However, that requires me to
> change all providers that currently "allocates" their states, so that
> isn't really a smooth way forward. Perhaps, we should simply print a
> message to the log about this condition in pm_genpd_init(), as to
> start with!? I can add a patch on top doing that.

Yes, that would make sense to track those providers which do not
initialize the free field.

Acked-by: Daniel Lezcano <daniel.lezcano@...aro.org>




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