我的移动宽带调制解调器（华为 E3276）在 Ubuntu 14.04 上出现问题。
lsusb 输出：
Bus 002 Device 024: ID 12d1:1506 Huawei Technologies Co., Ltd. E398 LTE/UMTS/GSM Modem/Networkcard
当我插入调制解调器时，/var/log/usb_modeswitch.log 中出现以下内容：
USB_ModeSwitch log from Fri Dec 5 22:52:36 2014
Use global config file: /etc/usb_modeswitch.conf
Started via upstart
Raw args from udev: /2-2
Bus ID for device not given by udev.
Trying to determine it from kernel name (2-2) ...
Use top device dir /sys/bus/usb/devices/2-2
USB dir exists: /sys/bus/usb/devices/2-2
Warning: USB attribute "serial" not readable.
SCSI dir exists: /sys/bus/usb/devices/2-2
Warning: …