Re: Attempted summary of suspend-blockers LKML thread

Paul E. McKenney
2010-08-07T14:36:20Z

On Sat, Aug 07, 2010 at 02:07:18PM +0100, Mark Brown wrote:
> On Fri, Aug 06, 2010 at 05:36:42PM -0700, Paul E. McKenney wrote:
> > On Sat, Aug 07, 2010 at 01:14:32AM +0100, Mark Brown wrote:
>
> > > services in themselves (like system monitoring). It's really just
> > > semantics to treat them differently to something like a cellular modem -
> > > at a high level they're both just independant processors ticking away
> > > without the application processor.
>
> > I agree that a smartphone's cellular modem can be argued to be very
> > similar to wake-on-LAN. The smartphone applications that seem to me
> > to be very different from wake-on-LAN are things like audio playback,
> > where the system is providing service to the user during the time that
> > it is suspended.
>
> The cellular modem case includes not just hanging off the network but
> also being on a call - the voice path for a phone call doesn't need the
> CPU to do anything. It's probably best to view a phone as a bunch of
> interconnected systems that happen to sit in the same box, and there's
> various design decisions that can be taken about which systems own the
> shared components.

OK, apologies, I thought you were talking about the wait-for-a-call case.
If there actually is a call ongoing, then the user perceives the system as
doing something, so this is similar to audio playback and quite different
from wake-on-LAN or system monitoring.

Thanx, Paul