Description of problem:

I have a Verizon Pantech UMW190 USB modem that worked fine with NetworkManager / ModemManager in Fedora 18.  I upgraded to Fedora 20 and find that it no longer works.

I also tried it with CentOS 7, and got the same result.

Version-Release number of selected component (if applicable):


How reproducible: 100%


Steps to Reproduce:
1. Plug in modem
2. Attempt to configure Mobile Broadband connection
3. Fail

Actual results:

ModemManager finds and tries to configure the device, but after that happens communication with the device is impossible.

# mmcli -m 0

/org/freedesktop/ModemManager1/Modem/0 (device id 'dd33b93220c7e018ee8eaab125dd13bb25061982')
  -------------------------
  Hardware |   manufacturer: 'PCD'
           |          model: 'UMW190VW'
           |       revision: 'W0190VWB222F.205  1  [Aug 28 2009 01:00:00] [Feb  8 2011 13:31:13]'
           |      supported: 'cdma-evdo, gsm-umts'
           |        current: 'cdma-evdo, gsm-umts'
           |   equipment id: '********'
  -------------------------
  System   |         device: '/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4'
           |        drivers: 'cdc_acm, qcaux'
           |         plugin: 'Pantech'
           |   primary port: 'ttyACM0'
           |          ports: 'ttyUSB1 (qcdm), ttyACM0 (at)'
  -------------------------
  Numbers  |           own : '**********'
  -------------------------
  Status   |           lock: 'none'
           | unlock retries: 'unknown'
           |          state: 'disabled'
           |    power state: 'on'
           |    access tech: 'unknown'
           | signal quality: '0' (cached)
  -------------------------
  Modes    |      supported: 'allowed: 2g, 3g; preferred: none'
           |        current: 'allowed: 2g, 3g; preferred: none'
  -------------------------
  Bands    |      supported: 'unknown'
           |        current: 'unknown'
  -------------------------
  IP       |      supported: 'ipv4, ipv6'
  -------------------------
  3GPP     |           imei: 'unknown'
           |  enabled locks: 'none'
           |    operator id: 'unknown'
           |  operator name: 'unknown'
           |   registration: 'unknown'
  -------------------------
  CDMA     |           meid: 'unknown'
           |            esn: '80BBCE9C'
           |            sid: 'unknown'
           |            nid: 'unknown'
           |   registration: CDMA1x 'unknown'
           |                 EV-DO  'unknown'
           |     activation: 'unknown'
  -------------------------
  SIM      |           path: '/org/freedesktop/ModemManager1/SIM/0'

I tried opening up a session with cu -l /dev/ttyACM0 to see if I could get any response to AT commands, but nothing.

Expected results:

It should work as before.

Additional info:

If I unplug the device, then disable ModemManager, then plug it back in and wait for it to settle, I can communicate AT commands to it with cu -l /dev/ttyACM0

Also, I have a successful workaround using wvdial (replace the *s with your mobile number and password):

- Create these files:

cat <<EOT > /etc/wvdial.conf
[Dialer Defaults]
Init = ATZ
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Modem Type = USB Modem
ISDN = 0
Phone = #777
Modem = /dev/ttyACM0
Username = **********@vzw3g.com
Password = ***
Baud = 460800
Stupid Mode = true
EOT

cat <<EOT > /etc/sysconfig/network-scripts/ifcfg-ppp0
DEVICE=ppp0
WVDIALSECT="Dialer Defaults"
MODEMPORT=/dev/ttyACM0
LINESPEED=460800
USERCTL=true
ONBOOT=no
PERSIST=no
DEFROUTE=yes
PEERDNS=yes
DEMAND=no
EOT

- Stop and disable ModemManager:

systemctl stop ModemManager.service
systemctl disable ModemManager.service

- (Unplug and) plug in device.

- Then, to bring up the interface do:

systemctl stop NetworkManager
ifup ppp0