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From:   Tri Vo <trong@android.com>
Date:   Tue, 6 Aug 2019 11:51:45 -0700
Message-ID: <CANA+-vBFY_mVfhhK=5BL5m_yyQ5+GTE9bv32fk-qsfnAmfE4nA@mail.gmail.com>
Subject: Re: [PATCH v7 3/3] PM / wakeup: Show wakeup sources stats in sysfs
To:     Stephen Boyd <swboyd@chromium.org>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Hridya Valsaraju <hridya@google.com>,
        Sandeep Patil <sspatil@google.com>,
        Kalesh Singh <kaleshsingh@google.com>,
        Ravi Chandra Sadineni <ravisadineni@chromium.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        "Cc: Android Kernel" <kernel-team@android.com>
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On Mon, Aug 5, 2019 at 4:29 PM Stephen Boyd <swboyd@chromium.org> wrote:
>
> Quoting Tri Vo (2019-08-05 10:58:48)
> > diff --git a/drivers/base/power/wakeup_stats.c b/drivers/base/power/wakeup_stats.c
> > new file mode 100644
> > index 000000000000..3a4f55028e27
> > --- /dev/null
> > +++ b/drivers/base/power/wakeup_stats.c
> > @@ -0,0 +1,161 @@
> [...]
> > +/**
> > + * wakeup_source_sysfs_add - Add wakeup_source attributes to sysfs.
> > + * @parent: Device given wakeup source is associated with (or NULL if virtual).
> > + * @ws: Wakeup source to be added in sysfs.
> > + */
> > +int wakeup_source_sysfs_add(struct device *parent, struct wakeup_source *ws)
> > +{
> > +       struct device *dev;
> > +
> > +       dev = device_create_with_groups(wakeup_class, parent, MKDEV(0, 0), ws,
> > +                                       wakeup_source_groups, "wakeup%d",
> > +                                       ws->id);
> > +       if (IS_ERR(dev))
> > +               return PTR_ERR(dev);
> > +       ws->dev = dev;
> > +       pm_runtime_no_callbacks(ws->dev);
>
> Does this only avoid adding runtime PM attributes?
>
> I thought we would call device_set_pm_not_required() on the device here.
> Probably requiring a bit of copy/paste from device_create_with_groups()
> so that it can be set before the device is registered. Or another
> version of device_create_with_groups() that does everything besides call
> device_add().

Comments on pm_runtime_no_callbacks() say,
  "Set the power.no_callbacks flag, which tells the PM core that this
   device is power-managed through its parent and has no runtime PM
   callbacks of its own.  The runtime sysfs attributes will be removed."

Sound like it's appropriate to apply this function to the wakeup source.