Re: Attempted summary of suspend-blockers LKML thread

From: Paul E. McKenney
Date: Thu Aug 05 2010 - 19:03:19 EST

On Thu, Aug 05, 2010 at 03:16:51PM -0700, Brian Swetland wrote:
> On Thu, Aug 5, 2010 at 3:09 PM, <david@xxxxxxx> wrote:
> >> Oops, yea that's actually a really bad example, that's probably
> >> something that would be handled by low-power states.  I think the
> >> incoming text message example is a good one though.  There seemed to
> >> be a focus on user-interaction scale time scales, and I wanted to
> >> point out that there are also very short duration time scales to
> >> consider as well.
> >
> > good point, but I do think the short time scales are less common than people
> > think.
> >
> > I'd love to get good examples of them
> >
> > on my iphone when a text message arrives the phone displays an alert for
> > user-interaction times (it even lights the display to show who the message
> > is from, and optionally a preview of the message)
> >
> > so what would wake a phone up from suspend where the phone should go back to
> > sleep in under a second?
> Here are some real-world examples from shipped android devices:
> - battery gauging happens every 10 minutes, need to wake long enough
> to chatter with the 1w interface and make sure the battery is not
> exploding
> - always on mail/im/calendar/etc sync often has network events that
> happen every 5-10 minutes which cause devices to briefly wake up and
> return to sleep
> - gps tracker app might wake every couple minutes or every n gps
> events to log location
> - low power audio subsystems can wake you up every 1-4 seconds (pcm)
> or 1-4 minutes (mp3) to fetch more data


So for an mp3 playback, does an Android suspend between data fetches?

Thanx, Paul
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