Re: Unable to connect to mobile broadband: +CME ERROR:30

[Dan Williams <dcbw redhat com>]

On Fri, 2010-10-15 at 15:53 +0200, van Schelve wrote:
> Am Donnerstag, den 14.10.2010, 11:09 +0200 schrieb Dan Williams
> <dcbw redhat com>:
> > On Thu, 2010-10-14 at 09:30 +0200, van Schelve wrote:
> >> Am Mittwoch, den 13.10.2010, 21:00 +0200 schrieb van Schelve
> >> <public van-schelve de>:
> >> > Am Mittwoch, den 13.10.2010, 12:49 +0200 schrieb Dan Williams
> >> > <dcbw redhat com>:
> >> >> On Mon, 2010-10-11 at 10:43 +0200, van Schelve wrote:
> >> >>> Hi,
> >> >>>
> >> >>> I found a different problem where I get reports from our users in the
> >> >>> field. They tell us that they are not able to connect to mobile
> >> >>> network.
> >> >>>
> >> >>> In the logs I captured I found a cme error 30 which means "No network
> >> >>> service". I tried it two or three times with still the same problem.
> >> >>> Then I tested with a second identical laptop with an identical setup
> >> >>> and I was able to bring up the mobile connection on this system without
> >> >>> any problem.
> >> >>>
> >> >>> So I decided to use the rfkill switch on the laptop where I found the
> >> >>> problem with the result that dialin was possible after doing th rfkill
> >> >>> cycle.
> >> >>
> >> >> Interesting; your module seems to have firmware 1.1.8.3, while I have 3
> >> >> different modules with 1.1.8.15, 1.1.9.3, and 2.0.8.19.  I think
> >> >> 2.0.8.19 screwed my device though, so don't try it.  I've noticed odd
> >> >> problems like this on other Sierra devices in the past that were solved
> >> >> by firmware updates (AC875 and AC881), but it's pretty hard to find
> >> >> firmware upgrades for their  embedded modules.  Do you know offhand if
> >> >> any of the devices in the field has other firmware than 1.1.8.3?
> >> >
> >> > We have completely identical hardware in the field. All the systems are
> >> > Lenovo Thinkpad T61 with identical BIOS 2.10 version and the same
> >> > firmware
> >> > on the embedded sierra device : 1.1.8.3. I think changing the firmware
> >> > to
> >> > a different version woud be a really bad option. Our systems are spread
> >> > all over germany and I don't think the firmware update would be
> >> > possible
> >> > under linux.
> >>
> >> I talked about this problem with a contact at SierraWireless. He said
> >> that
> >> a firmware upgrade will not help in this case. But what can help is
> >> checking
> >> for PS attach and dial only if PS attach status is attached. Dialing
> >> without
> >> PS attach can bring modem into unwanted condition that sometimes
> >> restart is
> >> needed to recover.
> > 
> > Hmm, interesting.  I'll try a few things out then.
> > 
> > Dan
> > 
> Hi Dan,
> 
> I got an additional hint I'll forward to you now:
> 
> "...
> Since you have enabled +CREG=2 notification for registration, there is
> no need to query registration status. Let the modem find the network and
> register and you will be notified. So, do not execute +CREG?
> Do not attempt PPP connection unless there is PS attach. As I mentioned
> before, check for PS attach status after you have received registration.
> ..."

Though executing +CREG? shouldnt' make a difference here, and MM wont'
proceed unless the modem says it's registered either via +CREG? explicit
response or via the unsolicited event.  They probably mean CGREG
instead?  CREG is for CS registration status, CGREG is for PS
registration status.

In any case, I pushed:

http://cgit.freedesktop.org/ModemManager/ModemManager/commit/?id=d63dcd682d3449b021f205af67dd0071e91cc56f

which should work around the issue for Sierra devices, can you test?

Thanks
Dan