Ubuntu hangs after replugging the modem

Question

I am facing this issue on Ubuntu 12.04, which is for my Wimax modem with beceem chipset.

If I replug the device Ubuntu goes in hang state. Its happens very often. If I plug the USB and restart it works most of the time. But it is very annoying to restart every time it hangs. The modem works smoothly in Windows 7. And it used to work OK in Ubuntu 11.10.

Jun 13 19:25:54 iftekhar-HP-520-Notebook-PC dbus[1102]: [system] Activating service name='org.freedesktop.UDisks' (using servicehelper)
Jun 13 19:25:54 iftekhar-HP-520-Notebook-PC dbus[1102]: [system] Successfully activated service 'org.freedesktop.UDisks'
Jun 13 19:26:00 iftekhar-HP-520-Notebook-PC goa[2168]: goa-daemon version 3.4.0 starting [main.c:112, main()]
Jun 13 19:26:47 iftekhar-HP-520-Notebook-PC udevd[432]: timeout 'cdrom_id --lock-media /dev/sr1'
Jun 13 19:26:48 iftekhar-HP-520-Notebook-PC udevd[432]: timeout: killing 'cdrom_id --lock-media /dev/sr1' [1072]
Jun 13 19:26:49 iftekhar-HP-520-Notebook-PC kernel: [   85.820162] sr 2:0:0:0: Device offlined - not ready after error recovery
Jun 13 19:26:49 iftekhar-HP-520-Notebook-PC udevd[432]: timeout: killing 'cdrom_id --lock-media /dev/sr1' [1072]
Jun 13 19:27:20  udevd[432]: last message repeated 31 times
Jun 13 19:27:25  udevd[432]: last message repeated 4 times

What can I do to avoid this hangs and restarts?

Answer 1

Though It will be very useful to include model number of your modem, I assume you are referring to the Banglalion Wimax modem with model ZTE AX226. I also have this same modem and this same problem. But I find a workaround for this problem.

Workaround to prevent the problem:

• Open a terminal, and type sudo gedit /etc/modules to open the /etc/modules file

• At the end of file, put a line with this bcm_wimax. This line tells the kernel to load the driver file, at boot time.

• Then run this command sudo depmod -a -e.

• Then sudo update-initramfs -u

• Then restart. This problem should never arise again after that.

But as a precaution, You can do this to prevent errors.
Open a terminal and type lsmod | grep bcm, if it returns a line like below,

    bcm_wimax             244941  2

You are free to insert the modem. If it does not return any line, you should do the following:

• Open a terminal and type sudo modprobe bcm_wimax to insert the module manually.

Note: From my experience, I see that, you have to wait around 10-15 seconds to get the driver ready. So, do not insert the modem after just running the command.