linux-kernel - Re: [PATCH v10 4/8] PM: domains: Add dev_get_performance

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <a705b35f-8ece-bf74-b7db-7c4ded19e43e@gmail.com>
Date:   Thu, 2 Sep 2021 11:42:37 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Ulf Hansson <ulf.hansson@...aro.org>
Cc:     Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        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 v10 4/8] PM: domains: Add dev_get_performance_state()
 callback

01.09.2021 19:59, Ulf Hansson пишет:
>> +static int genpd_dev_initialize_performance_state(struct device *dev,
>> +                                                 struct device *base_dev,
>> +                                                 unsigned int index)
>> +{
>> +       struct generic_pm_domain *pd = dev_to_genpd(dev);
>> +       bool state_default = false, suspended = false;
>> +       int pstate, err;
>> +
>> +       pstate = genpd_dev_get_current_performance_state(dev, base_dev, index,
>> +                                                        &state_default,
>> +                                                        &suspended);
>> +       if (pstate <= 0)
>> +               return pstate;
>> +
>> +       /*
>> +        * If device is suspended, then performance state will be applied
>> +        * on RPM-resume. This prevents potential extra power consumption
>> +        * if device won't be resumed soon.
>> +        *
>> +        * If device is known to be active at the moment, then the performance
>> +        * state should be updated immediately to sync state with hardware.
>> +        */
>> +       if (suspended) {
>> +               dev_gpd_data(dev)->rpm_pstate = pstate;
>> +       } else {
>> +               err = dev_pm_genpd_set_performance_state(dev, pstate);
>> +               if (err) {
>> +                       dev_err(dev, "failed to set performance state for power-domain %s: %d\n",
>> +                               pd->name, err);
>> +                       return err;
>> +               }
>> +
>> +               if (state_default)
>> +                       dev_gpd_data(dev)->default_pstate = pstate;
>> +       }
>> +
>> +       return 0;
>> +}
> As I kind of indicated in my previous reply on the earlier version, I
> think the above code can be made a lot less complicated. Although,
> perhaps I may be missing some points.
> 
> Anyway, I will post a couple patches, later this evening or tomorrow,
> to show more exactly what I had in mind. Let's see if that can work
> for you.

It's not obvious what you're wanting to improve, I'm probably missing
yours point. So indeed will be good to see the code sample, thanks.