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From:   Tri Vo <trong@android.com>
Date:   Wed, 31 Jul 2019 15:31:16 -0700
Message-ID: <CANA+-vDTDq__LnLBpM5u_VHHvpFA--K5Du63vPB7HfaKzBsPtg@mail.gmail.com>
Subject: Re: [PATCH v6] PM / wakeup: show wakeup sources stats in sysfs
To:     "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc:     Stephen Boyd <swboyd@chromium.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        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 Wed, Jul 31, 2019 at 3:17 PM Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
>
> On Wednesday, July 31, 2019 11:59:32 PM CEST Stephen Boyd wrote:
> > Quoting Tri Vo (2019-07-31 14:55:14)
> > > +/**
> > > + * 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;
> > > +       int id;
> > > +
> > > +       id = ida_alloc(&wakeup_ida, GFP_KERNEL);
>
> So can anyone remind me why the IDA thing is needed here at all?

IDA is used to generate the directory name ("ws%d", ID) that is unique
among wakeup_sources. That is what ends up in
/sys/class/wakeup/ws<ID>/* path.
>
> > > +       if (id < 0)
> > > +               return id;
> > > +       ws->id = id;
> > > +
> > > +       dev = device_create_with_groups(wakeup_class, parent, MKDEV(0, 0), ws,
> > > +                                       wakeup_source_groups, "ws%d",
> >
> > I thought the name was going to still be 'wakeupN'?
>
> So can't we prefix the wakeup source name with something like "wakeup:" or similar here?

"ws%d" here is the name in the sysfs path rather than the name of the
wakeup source. Wakeup source name is not altered in this patch.