[OpenWrt-Devel] mbim / Sierra Wireless AirCard 340U

Bjørn Mork bjorn at mork.no
Tue Apr 7 07:38:12 EDT 2015

John Crispin <blogic at openwrt.org> writes:
> On 07/04/2015 12:31, Bjørn Mork wrote:
>> David Hutchison <dhutchison at bluemesh.net> writes:
>>> Hello John,
>>> One of our customers use the 340U, and the latest firmware
>>> revision that fixes Windows 8 support.. broke linux support ( 
>>> http://mtekk.us/archives/guides/netgear-aircard-340u-linux/ ) We
>>> had to downgrade the firmware on the 340u itself.
>> Is this broken on linux with libmbim+ModemManager, or only with
>> umbim? Or is it just that the new version forces MBIM mode, while
>> the older allows QMI?  Or is the problem related to the QMI issues
>> discussed here: 
>> http://lists.freedesktop.org/archives/libqmi-devel/2014-August/000883.html
> the bug report comes from umbim it is a segfault that happens, not nice.

Looking further into what seems to be the real problem there: The
attach + connect failing with "message not long enough" errors.

The error message is a side effect of the fixed buffer size approach
taken by umbim.  It assumes that a response to attach/connect always
will have a MBIM_PACKET_SERVICE_INFO data buffer.  But that depends on
the status code, as described in " STATUS CODES".

In this case, the connect message fails with:

  MessageType:  0x80000003 (MBIM_COMMAND_DONE)
  MessageLength:        48
  TransactionId:        2
  TotalFragments:       0x00000001
  CurrentFragment:      0x00000000
BASIC_CONNECT (a289cc33-bcbb-8b4f-b6b0-133ec2aae6df)
InformationBuffer [0]:

which I assume happens because MBIM session was closed after
initialisation.  It could also be that we are missing some command
necessary to bring the modem up.

openwrt-devel mailing list
openwrt-devel at lists.openwrt.org

More information about the openwrt-devel mailing list