Re: Slightly incompatible GSM devices

[Dan Williams <dcbw redhat com>]

On Fri, 2009-02-13 at 07:32 +0000, Ingmar Steen wrote:
> Hi all,
> 
> First of all, sorry for not knowing all the exact terminology and jargon of the internals of NM. Hope I don't confuse you too much :)
> 
> I was trying to connect to the internet using my blackberry 8820 with bluetooth and NetworkManager + Blueman.
> 
> Blueman allowed me to advertise my bluetooth serial connection as a GSM type device to NetworkManager, which worked fine.
> 
> Then when trying to connect to my mobile broadband profile using NM, it just gave me the helpful message that the connection had failed (without mentioning why). I turned on the serial debugging and noticed that the modem initialisation seemed to fail. After experimenting with minicom, it seemed that the +fclass AT command doesn't work on this device. So I edited the NM gsm 'driver' and removed that.
> 
> Now my BB spontaneously rebooted when trying to connect (hey, at least something is doing something ;)). After some poking it turned out that the culprit was the automatic network selection. After bypassing that, my connection works.
> 
> Now, my question is, what is the best way to add support for these kind of deviant devices? Would it be best to allow some configurable overrides in NM's gsm driver to 'dumb it down' a bit so that blueman can advertise this device as GSM (with the 'stupid' flag set)? Or would it be best to copy the GSM driver and create a new StupidGSM device class? Another option would be a broadband profile option, but it's really a device thing and has nothing to do with the connection itself (some connection on different device would not need the stupidmode). Or should I just f*ck off with my evil proprietary stuff because it's not worthy to get all the networkmanager goodness?

The best solution is to quirk these devices in ModemManager.
Blackberries are notoriously proprietary, and if you look at the "barry"
sources for connecting the device via USB port, it's horrible what
they've had to do just to talk to the phone.  But it's not impossible to
create a ModemManager plugin that would account for the oddities of the
blackberry.

ModemManager is also on Freedesktop.org git.  Try
http://git.freedesktop.org and look for ModemManager.  Tambet is around
on these lists and can answer questions you have about it.

Dan