QMI/MBIM on Sierra Wireless MC7710

[Bjørn Mork]

Thomas Högler <thomas.hogler at anyway.se> writes:

> Hei Björn!
>
>  
>
> Vi är ett företag som jobbar med mobilt internet för M2M. En av våra kunder
> frågar om Sierra Wireless MC7710 stöder QMI/MBIM om man kör på en ”rå”
> Linuxplattform. Tyvärr ligger detta lite utanför mitt område och jag har
> ställt frågan direkt till Sierra, men får svårtydbara svar.
>
>  
>
> Bland annat, citat:
>
> “I believe your order SKU number about MC7710 should be based on DirectIP,
> if so it even cannot support QMI.
>
> I checked out PTS about MC7710 for MBIM it should support based on WIN8, but
> your platform is based on Linux,
>
> so MC7710 cannot support both QMI and MBIM based Linux platform.”
>
> slut citat.
>
>  
>
> Är det korrekt uppfattat att om man väljer en firmware med ”Direct IP” så
> stödjer den INTE QMI/MBIM ? Hur gör man då för att FÅ stöd för QMI/MBIM?

Better keep this in english since this was sent to an english mailing
list :)

No, that's not correct.  AFAIK, all recent MC7710 firmwares support all
of DirectIP, QMI and MBIM.

The MC7710 can be configured for either "DirectIP" or "QMI" mode,
regardless of SKU. You switch between these modes using a password
protected AT command.  The procedure is documented by Sierra Wireless in
their developer documentation, and also here:

  http://forum.sierrawireless.com/viewtopic.php?f=117&t=6759#p28436

The password is supposed to be available only to OEMs, and it can be
changed by the OEMs.  My experience is that the one found here often
will work:

  http://bc.whirlpool.net.au/bc/hardware/?action=h_view&model_id=1210

Note that we must assume there is a good reason for password protecting
these commands.  They change settings which may cause device
malfunction.  Consider this a warning.  Don't try any password protected
command without reading the documentation first...

Regarding the MC7710 DirectIP vs QMI SKUs, it is my impression that the
only difference is which mode the firmware operates in by default.  At
least I haven't been able to find any other difference.  It is
definitely possible to change the DirectIP SKU into QMI mode using the
command referenced above.

As for MBIM, it is supported in QMI mode in the latest released firmware
version, which AFAIK is SWI9200X_03.05.19.04ap.  You switch between QMI
and MBIM by simply switching USB configurations (but the firmware
implementation is very buggy, so you probably should select one
configuration immediately after resetting the module, and stay with that
one until the next reset).

Linux includes drivers for MBIM (from v3.8), QMI (from v3.4) and
DirectIP (from v2.6.34), so all modes and configurations are supported
by the mainline Linux.

Sierra Wireless provides a Linux QMI SDK (based on Qualcomm's SDK), but
this is not open source and it requires the out-of-tree GobiNet driver.
This is mostly important to know because that's their reference point
wrt QMI support.  I recommend using the qmi_wwan driver instead (of
course :), and one of the open source QMI userspace solutions, like e.g
libqmi.


Bjørn