Huawei ME909u, lte capabilities not reported by ModemManager (yet, it connects to lte)

[Aleksander Morgado]

On Tue, Nov 24, 2015 at 3:57 PM, José <Joseddg92 at gmail.com> wrote:
> I am using a the Huawei ME909u, a modem with lte capabilites, with
> ModemManager. Using mmcli -m 0 shows only 'gsm-umts' capabilities,but
> it reports that the device is connected to a lte netwokr.
>
> root at ccimx6sbc:~# mmcli -m 0
>
> /org/freedesktop/ModemManager1/Modem/0 (device id
> 'f1f88882f8d5d70ed30e060f6e0f9b2d149b1a5f')
>
>   -------------------------
>   Hardware |   manufacturer: 'Huawei Technologies Co., Ltd.'
>            |          model: 'ME909u-521'
>            |       revision: '11.234.77.00.00'
>            |      supported: 'gsm-umts'
>            |        current: 'gsm-umts'
>            |   equipment id: '860461024718192'
>   -------------------------
>   System   |         device:
> '/sys/devices/soc0/soc.1/2100000.aips-bus/2184200.usb/ci_hdrc.1/usb1/1-1/1-1.3'
>            |        drivers: 'option1, cdc_ether'
>            |         plugin: 'Huawei'
>            |   primary port: 'ttyUSB2'
>            |          ports: 'eth1 (net), ttyUSB0 (at), ttyUSB2 (at)'
>   -------------------------
>   Numbers  |           own : 'unknown'
>   -------------------------
>   Status   |           lock: 'none'
>            | unlock retries: 'sim-pin (3), sim-pin2 (3), sim-puk (10),
> sim-puk2 (10)'
>            |          state: 'connected'
>            |    power state: 'on'
>            |    access tech: 'lte'
>            | signal quality: '60' (recent)
>   -------------------------
>   Modes    |      supported: 'allowed: 4g; preferred: none
>            |                  allowed: 3g; preferred: none
>            |                  allowed: 2g; preferred: none
>            |                  allowed: 2g, 3g, 4g; preferred: none'
>            |        current: 'allowed: 2g, 3g, 4g; preferred: none'
>   -------------------------
>   Bands    |      supported: 'unknown'
>            |        current: 'unknown'
>   -------------------------
>   IP       |      supported: 'ipv4, ipv6, ipv4v6'
>   -------------------------
>   3GPP     |           imei: '860461024718192'
>            |  enabled locks: 'sim'
>            |    operator id: '21404'
>            |  operator name: 'YOIGO Yoigo'
>            |   subscription: 'unknown'
>            |   registration: 'home'
>   -------------------------
>   SIM      |           path: '/org/freedesktop/ModemManager1/SIM/0'
>   -------------------------
>   Bearers  |          paths: '/org/freedesktop/ModemManager1/Bearer/0'
>
>
> The modem works properly with showing 4G-like speed.
>
> I have tried updated the firmware and the behaviour is the same.
>
> Seems like a ModemManager bug to me, so I am reporting just in case.
>
> Here is the complet debug log: http://pastebin.com/zs6uJXVK

The Huawei modem doesn't reply as expected to any of the generic tests
we do to query for capabilities; and we end up falling back to say
"gsm-umts" as it requests for SIM-PIN, which is the last fallback test
we do IIRC.

But, we do use AT^SYSCFGEX later to load current modes, and that one
reports being LTE-capable ("03"):

<debug> (ttyUSB2): --> 'AT^SYSCFGEX=?<CR>'
<debug> (ttyUSB2): <-- '<CR><LF>^SYSCFGEX:
("00","03","02","01","99"),((2000004e80380,"GSM850/GSM900/GSM1800/GSM1900/WCDMA850/WCDMA900/WCDMA1900/WCDMA2100"),(3fffffff,"All
Bands")),(0-3),(0-4),((800d7,"LTE1900/LTE2100/LTE2600/LTE1800/LTE900/LTEDD800/LTE850"),(7fffffffffffffff,"All
Bands"))<CR><LF><CR><LF>OK<CR><LF>'

The Huawei plugin should subclass load_current_capabilities() (see
e.g. the altair-lte plugin) in order to provide a custom check based
on AT^SYSCFGEX (which we already can parse in
mm_huawei_parse_syscfgex_test()) in addition to the generic checks.

Would you be willing to develop the fix? :)

-- 
Aleksander
https://aleksander.es