title: ModemManager: mmcli get signal strength
body: <p>I am unable to retrieve the signal strength on a Sierre Wireless MC7304.<br>
  Also sending an AT command via mmcli does not seem to work.  </p>
  
  <pre><code>:~ $ sudo mmcli -m /org/freedesktop/ModemManager1/Modem/0 --signal-get
   error: modem has no extended signal capabilities
  
  :~ $ sudo mmcli -m /org/freedesktop/ModemManager1/Modem/0 --command=AT+CSQ
  error: command failed: 'GDBus.Error:org.freedesktop.ModemManager1.Error.Core.Unauthorized: Cannot send AT command to modem: operation only allowed in debug mode'
  
  
  /org/freedesktop/ModemManager1/Modem/0 (device id 
  'dd26a5483d051c6e25a7ca10f4d36a94791c7ebf')
  -------------------------
  Hardware |   manufacturer: 'Sierra Wireless, Incorporated'
         |          model: 'MC7304'
         |       revision: 'SWI9X15C_05.05.16.02 r21040 carmd-fwbuild1 
  2014/03/17 23:49:48'
         |      supported: 'gsm-umts, lte'
         |        current: 'gsm-umts, lte'
         |   equipment id: 'unknown'
   -------------------------
    System   |         device: 
  '/sys/devices/platform/soc/3f980000.usb/usb1/1-1/1-1.5'
         |        drivers: 'qmi_wwan, qcserial'
         |         plugin: 'Gobi'
         |   primary port: 'ttyUSB2'
         |          ports: 'ttyUSB0 (qcdm), ttyUSB2 (at), wwan0 (net), 
  wwan1 (net)'
  -------------------------
   Numbers  |           own : 'unknown'
   -------------------------
   Status   |           lock: 'none'
         | unlock retries: 'unknown'
         |          state: 'connected'
         |    power state: 'on'
         |    access tech: 'lte'
         | signal quality: '0' (recent)
   -------------------------
   Modes    |      supported: '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: 'unknown'
         |  enabled locks: 'none'
         |    operator id: 'hidden'
         |  operator name: 'hidden'
         |   subscription: 'unknown'
         |   registration: 'home'
   -------------------------
   SIM      |           path: '/org/freedesktop/ModemManager1/SIM/0'
  
   -------------------------
    Bearers  |          paths: '/org/freedesktop/ModemManager1/Bearer/0'
  </code></pre>
  
  <p>When using the modem inside for example an Mikrotik 922 card i seem to get the signal strength just fine.<br>
  I am using mmcli version: 1.4.0-1 and Kernel 4.450 on a raspberry pi.</p>