Marketed by various telecommunications companies in several countries, the E220 is a 3.5G HSDPA USB modem used mainly for wireless Internet access via mobile telephony networks. Technically it is a modem, USB and (due to the CDFS format) CD-ROM device. With a kernel version older than 2.6.20, getting Linux to recognize the device as a modem and accessing its functions requires a workaround.
"Linux kernel versions prior to 2.6.20 have some problems with it, as the SCSI CDROM fakevolume with drivers for Microsoft systems gets automounted by usbstorage.ko module, preventing serial device /dev/ttyUSB0 from working properly."
However, as support for it was added in 2.6.20 via modules usb-storage and usbserial, getting it to work is as simple as plugging it in and dialling up (the above statement is of no concern to us as we can load and unload modules at will, it was probably meant for pre-packaged GNU and Linux distributions). In fact, using the modem under Linux proves to be more reliable as there are no uncalled-for disconnections. This is probably due to the fact that we are communicating directly with the modem, whereas in Windows or Mac OS X drivers are installed on first run (that is what the storage portion is for) and connection is achieved through a thick software layer every time, leaving room for possible interferences and conflicts.
Archers do not use old stuff, let alone use old kernels. That is, however, not enough reason to explain why in some cases the modem still needs the workaround. Thus, you have to see for yourself if you are one of the lucky ones. It almost seems as if the "support" in kernels > 2.6.20 is a myth, although that may be entirely incorrect (maybe it is how Arch developers package the vanilla kernels in which case we have only phrakkkture and gang to thank).
The magic (trick) lies in the kernel modules; unloading, blacklisting, reloading and loading things will get it done.
After hooking up to the USB port (some say an upright position is best; let it hang over the edge of the desk), check to make sure it is detected.
$ cat /proc/bus/usb/devices
You should see Huawei somewhere there. If not, you are on your own. The usb-storage and/or usbserial modules must be loaded, whether manually or by HAL is up to you and/or your system.
# modprobe usb-storage # modprobe usbserial $ sleep 6 # the modem may take a while to initialize $ ls /dev/ttyUSB*
You should see three renditions of ttyUSB. If not, we will get to that later. This is a "Quick Start" after all, no? The ports:
- ttyUSB0 - Modem
- ttyUSB1 - USB?
- ttyUSB2 - Nothing
Now you need a dialler. Most convenient of all would be wvdial, so install it. You should have ppp already, if not just pull them both in.
# pacman -Sy wvdial ppp
Most SIM and data services provided together with the device do not require special settings and work with similar configuration to get connected. They are almost "Plug n' Play", a special trait of Linux. Edit /etc/wvdial.conf and use something like the following:
[Dialer hsdpa] Phone = *99***16# Username = 65 Password = user123 Stupid Mode = 1 Dial Command = ATDT Modem = /dev/ttyUSB0 Baud = 460800 Init2 = ATZ Init3 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 ISDN = 0 Modem Type = Analog Modem
There is an example here by a "Linux Guru". Then load the PPP module.
# modprobe ppp-generic
You can now connect immediately, but probably only as root, which is not a disadvantage.
# wvdial hsdpa
So why then? Well, for some reason those of us on newer kernels still have to ride the old ways. In some cases, all that is needed to be done is to remove the usb-storage module first, then load usbserial with the device IDs. The first cat command on this page will have that information, while lsusb is an alternative. Anyhow, the IDs are the same for almost all E220s, so you can copy wholesale.
# modprobe -r usb-storage usbserial # modprobe usbserial vendor=0x12d1 product=0x1003
When you cannot salvage anything from this either, you have to go Gentoo and compile something. Do not worry, it is only a script and we do things like this almost everyday, albeit in bash.
$ mkdir ~/huawei-e220 && cd ~/huawei-e220 $ wget http://www.kanoistika.sk/bobovsky/archiv/umts/huaweiAktBbo.c $ gcc -o e220 *.c # ./e220
This gets around the kernel to recognize the modem functionalities of the device. You can now carry on and connect using the above methods. If you had to follow this step, you will always need the script unless you set udev rules and such (package link below). So move it to a global PATH.
$ cd ~/huawei-e220 # mv e220 /usr/bin/e220
Now it is easier.
Note: It seems some people get it to work using ttyUSB1, which should not be the case, but rest assured that at least on recent kernels and systems ttyUSB0 is the correct port to dial with.
To check if the device is functioning alright on a particular serial port, there is a program for probing serial devices.
# pacman -S minicom
Now run it.
# minicom -s
Change the serial port to /dev/ttyUSB1 and exit from the page, this will open the main program. When it initializes the modem, issue the command AT. The answer should be OK, which means the modem is working well on that port.