[Gta04-owner] Modem reenummerating (was: Re: Crowdfunding an Ubuntu smartphone)

[Dr. H. Nikolaus Schaller]

Am 30.08.2013 um 08:07 schrieb Radek Polak:

> On Thursday, August 29, 2013 01:00:54 PM Dr. H. Nikolaus Schaller wrote:
> > Am 29.08.2013 um 12:56 schrieb Radek Polak:
> > > On Thursday, August 29, 2013 11:50:26 AM Dr. H. Nikolaus Schaller wrote:
> > > > Am 29.08.2013 um 10:50 schrieb Radek Polak:
> > > > 
> > > > Looks like becoming a Heisenberg-Bug. The closer you look the less you
> > > > can grab it...
> > > 
> > > unfortunately yes...
> > > 
> > > > > I think that it has lost it after playing with AT_OPSYS. My GTA04 is
> > > > > brand new and i havent used AT_OPSYS command until yesterday.
> > > > 
> > > > Unfortunately I don't know what the factory setting is.
> > > 
> > > You can use AT_OPSYS? to find out on brand new GTA04 board if such board
> > > exists.
> > 
> > Hm. I don't think so :( All of them have been tested including some modem
> > commands... So unless we produce more, there is no really virgin GTA04
> > board :(
>  
> I think "some AT commands" dont matter unless you did AT_OPSYS.
>  
> Btw mine phone is now very stable. 315 calls and 0 reenumerates.

If I get it right, this is with OPSYS=0,2.

Hm. What I still don't get into a clear hypothesis is that it depends on
2G vs. 3G AND suspend vs. no suspend.

If it would show up only when using suspend I would conjecture that
the EHCI/USB interface does not handle CPU suspends correctly. Maybe
irritating the modem which might not be prepared that the host is suspending
or getting into a bad state [1]

But the dependence on 2G vs. 3G does not fit into this picture.

BTW: in my setup I still have to try to find out why my GTA04 used for testing
only sees 2G (AT_ONCI?) - even if I issue OPSYS=3,2. Maybe I have played
with some other (persistent) settings of the modem. So at the moment I can't
try to reproduce 3G reenumerations.

-- hns

[1] this reminds me of a known errata of the OMAP3/USB3322 combination:

http://www.ti.com/lit/er/sprz319e/sprz319e.pdf

Advisory 1.44 and Advisory 1.64

Especially the second one looks suspicious - and may need to use the
RESET line of the 3322 in some cases.