I further investigated this bug. I can in fact use my internal USB 3G modem 12d1:14f1 (Huawei EM680) with both kernel modules, qcserial.ko and option.ko.
Usage with qcserial.ko was always working out-of-the-box (including support through NetworkManager) on precise and before. Since linux-image-3.2.0-32-generic, the option.ko module has to be blacklisted to keep the modem working through qcserial.ko. Usage with option.ko is nevertheless possible, if user space adapts and talks to the device on /dev/ttyUSB2 instead of /dev/ttyUSB1. While qcserial does create two serial devices, option favors creating three (/dev/ttyUSB[012]) instead. In both cases, it is possible to identify the device as a GSM modem through the last serial device using AT commands with the attached chat script probe_modem.chat (from https://wiki.ubuntu.com/NetworkManager/Hardware/3G/Probing): # using qcserial.ko $ chat -s -f ./probe_modem.chat > /dev/ttyUSB1 < /dev/ttyUSB1 chat: Dec 26 19:39:19 +GCAP: +CGSM,+DS,+ES chat: Dec 26 19:39:19 +COPS: 0,0,"Telekom.de",2 chat: Dec 26 19:39:19 +CREG: 0,1 # using option.ko $ sudo modprobe -r qcserial $ sudo modprobe option $ chat -s -f ./probe_modem.chat > /dev/ttyUSB2 < /dev/ttyUSB2 chat: Dec 26 19:39:42 +GCAP: +CGSM,+DS,+ES chat: Dec 26 19:39:42 +COPS: 0,0,"Telekom.de",2 chat: Dec 26 19:39:42 +CREG: 0,1 Also, one can successfully establish a connection using wvdial with both drivers, explicitly specifying the correct serial device in /etc/wvdial.conf in a manual fashion. Yet the device is only useable with NetworkManager (nmcli, applets) together with qcserial.ko, since modem-manager does only seem to expose the modem on d-bus if the qcserial driver is used. With option.ko, and therefore with current Ubuntu 12.04 LTS / precise, the device is not working out-of-the-box anymore, rendering this report a clear regression bug. Whether the regression is at the fault of the kernel or the modem-manager package is anyone's call. The kernel package did integrate an incompatible default driver change for the device that supposedly got committed upstream, while modem-manager should clearly be capable to find the device when operated through option.ko as well as qcserial.ko. ** Attachment added: "probe_modem.chat" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1079359/+attachment/3468349/+files/probe_modem.chat -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1079359 Title: 3.2.0-32 drops huawei modem To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1079359/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
