Re: [RFD] Automatic suspend

Rafael J. Wysocki
2009-02-20T10:49:36Z

On Friday 20 February 2009, Arve Hjønnevåg wrote:
> On Thu, Feb 19, 2009 at 2:08 PM, Alan Stern <stern@rowland.harvard.edu> wrote:
> >> > It might have to be platform-specific. The Android people seem to have a
> >> > pretty good idea of what criteria will work for them.
> >>
> >> I'd really like to know in what situations Androind is supposed to suspend
> >> automatically.
> >
> > It might be better to ask in what situations Android is _not_ supposed
> > to sleep automatically. In other words, in what situations is a
> > wakelock acquired? Since the whole system is only a phone, this
> > question should have a reasonably well-defined answer.
>
> On an android phone, any code that needs to run when the screen is off
> must hold a wakelock (directly or indirectly). In general if an
> application or the system is processing an event that may cause a user
> notification (new email, incoming phone call, alarm, etc.) it needs to
> prevent suspend. But, we also use wakelocks to upload stats or
> download system updates in the background, and for media player or
> (gps) data logging applications.

All of this doesn't seem to require wakelocks acuired from kernel space.
What do you need those wakelocks for?

Rafael