Re: [MM] grabbing QMI/WDM ports

[Bjørn Mork <bjorn mork no>]

Aleksander Morgado <aleksander lanedo com> writes:

>> The classical example is the Ericsson MBM modems used in Lenovo and Dell
>> laptops, which present AT command cdc-wdm interfaces.  ModemManager
>> should collect these and use them if necessary.
>>
>
> So those cdc-wdm interfaces are pure AT ports, no QMI involved in
> there?

Yes. But the driver isn't a tty driver so you cannot use the normal tty
ioctls to set it up.  Just open and read/write:

 bjorn@nemi:~$ cat /dev/cdc-wdm0 &
 [2] 6669
 bjorn@nemi:~$ echo -e "ATI\r" >/dev/cdc-wdm0
 bjorn@nemi:~$ ATI
 F3507g
 
 OK

Issuing unsupported tty ioctls does no harm of course, but you'll have
to ignore the errors if you do so. And you can of course not run PPP
over the cdc-wdm devices.  They are pure AT command channels.

> Then we can include AT probing for these ports as well, and if
> they are not AT assume they are QMI; or even setup new QMI probing as
> well.

I believe that should work fine. I've been doing it for a while with a
primitive perl script, and neither the Ericsson nor the Huawei modem
have any problems when being probed for the wrong protocol.


Bjørn