Re: A desktop environment[1] kernel wishlist

Bastien Nocera
2014-10-27T14:21:50Z

On Tue, 2014-10-21 at 20:24 +0200, Geert Uytterhoeven wrote:
> On Tue, Oct 21, 2014 at 7:14 PM, Bastien Nocera <hadess@hadess.net> wrote:
> >> As for: 'Export of "wake reason" when the system wakes up (rtc alarm,
> >> lid open, etc.) and wakealarm (/sys/class/rtc/foo/wakealarm)
> >> documentation'
> >>
> >> Can you expand more on the rational for the need here? Is this for UI
> >> for power debugging, or something else?
> >
> > No, it would be used for automating backups, or implementing
> > suspend->hibernation transitions. For example, right before the machine
> > suspends, I would schedule it to wake up in a hour. If I get woken up by
> > the rtc alarm (and not by the user through a lid open), I might:
> > - check that I'm plugged into the AC, it's night, and in the vicinity of
> > the server that handles my backups and so backup the system.
> > - check whether the battery is low, and hibernate the machine (if it
> > supports it, obviously).
>
> Isn't this already available through /sys/kernel/debug/wakeup_sources
> and/or the various power/wake* files in sysfs?

That might very well be, but /sys/kernel/debug/wakeup_sources really
isn't much of a user-space API. Where's the documentation for the
various power/wake* files?

As in my mail to John, that information might already be available
within the kernel, but it's not exported in a sensible way to
user-space.