Huawei ME906s does not connect

[Bjørn Mork]

Philipp Hagemeister <phihag at phihag.de> writes:

> My Huawei ME906s in a Lenovo T460p failed to connect on debian unstable,
> Fedora 24, as well as Windows 10. How can I find out what's wrong? I
> have verified that the (German T-Mobile) SIM card is PIN-free and works
> in an Android phone.
>
> I see a network device on debian and Fedora, but it shows up as NO-CARRIER:
>
> $ ip link
> ...
> 6: enp0s20f0u5c2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc
> pfifo_fast state DOWN mode DEFAULT group default qlen 1000
>     link/ether 02:1e:10:1f:00:00 brd ff:ff:ff:ff:ff:ff
>
> Unsurprisingly, dhclient fails when manually invoked. Since
> NetworkManager did not give me any error message (it just shows the
> network as perpetually connecting), I went ahead and killed ModemManager.


I don't know how to use that modem in CDC ECM mode, but I believe
Andreas Fett got it sort of working in MBIM mode by doing

 echo 0 > /sys/bus/usb/devices/1-2/bConfigurationValue
 echo 3 > /sys/bus/usb/devices/1-2/bConfigurationValue
 echo Y > /sys/class/net/wwan0/cdc_ncm/ndp_to_end


See the long thread starting at
https://lists.freedesktop.org/archives/modemmanager-devel/2016-March/002726.html

The last step will not be necessary in v4.7-rc4.  "ndp_to_end" is the
default for all Huawei modems since v4.6.  Note that you may have to
change the "1-2" to whatever bus-port your modem is connected to.

The first step is a firmware bug, but assumed to be required.  There are
probably timing issues here too, so I would recommend sleeping a second
or two between those to requests.  If this works for you and you are
satisfied using the modem in MBIM mode, then I recommend adding an udev
rule or similar to do this configuration switch automatically.


Bjørn