[Gta04-owner] Modem crashing?

xdrudis xdrudis at tinet.cat
Sat Feb 18 06:14:44 CET 2012


On Fri, Feb 17, 2012 at 04:56:03PM +0100, Marcel Holtmann wrote:
> Hi Butrus,
> 
> > > we already fixed this bug with CLCC polling inside oFono. That is not
> > > the problem.
> > >
> > > The one thing that nobody realizes here is that this workaround comes at
> > > a high price. You have to do constant polling while being in an active
> > > call.
> > 
> > Really _constant_? Would it be enough to wake once in 2 or 5 seconds
> > (or so)? How much time would one "poll" take? If e.g. it would take
> > say 100ms and you wake every 5 seconds (for example), the overall
> > power consumption would be reduced drastically...
> 
> we poll every 500ms since that is the expected latency that we can
> expect from a user. Anything less we result in bad user experience.

Ok. If I understood correctly we have a GSM chip that isn't able to
wake up the system when it detects a remote hangup in a voice call. So
when must keep the cpu and usb path awake too often to poll the GSM
chip and that drains battery.

Since we can't get another chip, we can't get 0 polls, but next best
thing we want is as few polls as possible. But we want to detect end
of call as close as possible to the real hangup. 

I wonder if there is any possible "hardware heurism" we can use. Is
there any possibility, ideally with the current hardware, or maybe
with simple electronic additions, that we can detect a change in some
parameter correlated with active voice call ?. For instance do we have
something that can wake the cpu up (so it can poll once and detect end
of call or go back to sleep or change the poll interval) when:

- volume in all of mic, speaker or headphone during last 0.5 s has been
lower than previous 1.5 s

- radio emission power has been lower in last 0.5s than was during previous
1.5 s (problem, we want to know about reception too, I guess, since it
may be the other side speaking).

- total power use (battery drainage) has been lower last 0.5 s than previous
1.5 s

And another question is about voIP. I've never used it. I guess we
don't have end of call problems with it. Does it consume more battery
than GSM voice ? Is it usable only in fewer places (less coverage)?





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