Re: 1199:6832 Sierra Wireless, Inc. MC8780 not working with NetworkManager 0.8.3.998 / ModemManager 0.4

[Pantelis Koukousoulas <pktoss gmail com>]

On Fri, May 20, 2011 at 10:10 AM, Aleksander Morgado
<aleksander lanedo com> wrote:
>
>> >
>> >  From a cursory reading of the bug reports you cited it seems like some
>> > sierra modems crash when ModemManager sends CFUN=1 to them.
>> >
>> > Can you help verify if this is indeed the case with yours as well?
>> >
>
> So it really seems that not only Wavecom modems get a whole software
> restart (including USB stack) when they get AT+CFUN=1. The thing is, is
> removing the power-up command a solution for *all* Sierra modems or are
> there any Sierra modems that really need the power-up command? If so,
> we'll probably need to disable the power-up only for specific models,
> like the one reported in the bug; or the other way around, enable it
> only for only some specific models.

>From reading the cited bug reports and from general "instict" I would think
that probably some of them need CFUN=1 and others crash when they get it
so the best thing to do is enable it selectively. (We can start from this
USBID and expand).

Unfortunately I don't have the device myself, so I can't test.


> Wasn't that patch already applied to Ubuntu's MM? According to the logs
> in https://bugs.launchpad.net/ubuntu/+source/modemmanager/+bug/459052
> that was written by Alexander Sack long ago, and possibly applied in
> Ubuntu... (comment #7?)

It was probably applied to ubuntu once but somehow it got dropped (I think
during the karmic -> lucid transition if I read well).

In the current version (natty) there is no such patch from what I could see.

In any case, a distro-local patch is really a bad idea for solving this type
of problems, especially when you have such a friendly and responsive
upstream like in this case.

Unfortunately I don't have any modemmanager experience or time to
implement the quirk "the right way", so if someone can start from
the previous attached patch and fix the problem correctly, it would be
great :)

Thanks,
Pantelis