OpenWRT - MC7455 (MBIM) not working as expected.

[Aleksander Morgado]

Hey,

On Mon, Jan 23, 2017 at 2:20 PM, Mark Wahlert <mark.wahlert at gmail.com> wrote:
> Hello.  I've built OpenWrt from trunk (Kernel 4.4.14) including ModemManager
> and its dependencies.
>
> With my mc7455 in QMI mode, PPP interface is established and the internet is
> accessible.
>
> With modem in MBIM mode, expected interface (not PPP) is brought online -
> although strangely with an IP from an entirely different network (than when
> in QMI), and the internet is not reachable.
>
> Please bear with me - I'm new to all of this.  Some outputs attached:
>
> Found 1 modems:
> /org/freedesktop/ModemManager1/Modem/0 [Sierra] MBIM [1199:9071]
>
> /org/freedesktop/ModemManager1/Modem/0 (device id
> '1404de2498fc8078e94bc55ab5ac5e4872bbf081')
>   -------------------------
>   Hardware |   manufacturer: 'Sierra'
>            |          model: 'MBIM [1199:9071]'
>            |       revision: 'SWI9X30C_02.20.03.00'
>            |      supported: 'gsm-umts, lte'
>            |        current: 'gsm-umts, lte'
>            |   equipment id: 'XXXXXXXXXXXXXX'
>   -------------------------
>   System   |         device:
> '/sys/devices/platform/ehci-platform.1/usb2/2-1'
>            |        drivers: 'che l'
>            |         plugin: 'Sierra'
>            |   primary port: 'cdc-wdm0'
>            |          ports: 'ttyUSB0 (qcdm), ttyUSB1 (at), cdc-wdm0 (mbim),
> wwan0 (net)'
>   -------------------------
>   Numbers  |           own : 'unknown'
>   -------------------------
>   Status   |           lock: 'none'
>            | unlock retries: 'sim-pin2 (3)'
>            |          state: 'registered'
>            |    power state: 'on'
>            |    access tech: 'lte'
>            | signal quality: '19' (cached)
>   -------------------------
>   Modes    |      supported: 'allowed: 3g, 4g; preferred: none'
>            |        current: 'allowed: 3g, 4g; preferred: none'
>   -------------------------
>   Bands    |      supported: 'unknown'
>            |        current: 'unknown'
>   -------------------------
>   IP       |      supported: 'ipv4, ipv6, ipv4v6'
>   -------------------------
>   3GPP     |           imei: 'XXXXXXXXXXXXX'
>            |  enabled locks: 'fixed-dialing'
>            |    operator id: '310120'
>            |  operator name: 'Sprint'
>            |   subscription: 'unknown'
>            |   registration: 'home'
>   -------------------------
>   SIM      |           path: '/org/freedesktop/ModemManager1/SIM/0'
>
>   -------------------------
>   Bearers  |          paths: '/org/freedesktop/ModemManager1/Bearer/4'
>
> config interface 'wwan'
> option device '/sys/devices/platform/ehci-platform.1/usb2/2-1'
> option proto 'modemmanager'
> option apn  'X.XX.XXXXX'
> option lowpower '1'
>
> wwan0     Link encap:Ethernet  HWaddr 5A:60:06:DC:00:57
>           inet addr:XX.XX.XXX.XX  Bcast:XX.XX.XXX.XX  Mask:255.255.255.252
>           inet6 addr: fe80::5860:6ff:fedc:57/64 Scope:Link
>           UP BROADCAST RUNNING NOARP MULTICAST  MTU:1500  Metric:1
>           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:817 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:1000
>           RX bytes:0 (0.0 B)  TX bytes:51020 (49.8 KiB)
>
> default via XX.XX.XXX.XX dev wwan0  src XX.XX.XXX.XX
> XX.XX.XXX.XX/29 dev wwan0  src XX.XX.XXX.XX
>
> For comparison sake - the modem works as expected in both QMI and MBIM mode
> on Ubuntu 16.10 which has raw-ip support in the updated qmi_wwan driver.
> I'd still expect OpenWrt with kernel 4.4 to work properly in MBIM.
>
> Thank you for any help you can provide.

It looks like "mmcli" is saying the modem is "registered" (i.e. not
connected). Could you also validate that by checking the bearer info,
e.g. "mmcli -b 4"?
Maybe the modem was connected briefly and then we didn't handle a
network disconnection properly, or something.

It would also be a good idea to retrieve ModemManager debug logs; you
can modify the MM daemon init file and add --debug
--log-file=/var/log/mm.log to get them.

-- 
Aleksander
https://aleksander.es