sudo modprobe -r uhci_hcd
sudo modprobe uhci_hcd

If that short version of my solution doesn’t help, please read ahead…

I’ve been trying to get this modem to work with Gutsy Gibbon, but the online howtos that I found on the net doesnt reliably work for me.

Weird enough for me initially as sometime I can just use wvdial (more on this afterward) and get connected, while most of the time I got various errors about the modem. With these non-reproducible errors and successes, I do some trial and error while looking at the kernel logs, and came up with this one final observation;

shakir@herugrim ~ $ uname -r  # just to show the kernel I'm using, as your mileage may vary
2.6.22-14-generic

At one shell I run this to see kernel messages;

sudo tail -f  /var/log/messages

and got this messages upon plugging in my Huawei E220 to the USB port;

usb 3-1: new full speed USB device using uhci_hcd and address 5
usb 3-1: configuration #1 chosen from 1 choice
usbcore: registered new interface driver libusual
usbcore: registered new interface driver usbserial
/build/buildd/linux-source-2.6.22-2.6.22/drivers/usb/serial/usb-serial.c: USB Serial support registered for generic
usbcore: registered new interface driver usbserial_generic
/build/buildd/linux-source-2.6.22-2.6.22/drivers/usb/serial/usb-serial.c: USB Serial Driver core
/build/buildd/linux-source-2.6.22-2.6.22/drivers/usb/serial/usb-serial.c: USB Serial support registered for GSM modem (1-port)
option 3-1:1.0: GSM modem (1-port) converter detected
usb 3-1: GSM modem (1-port) converter now attached to ttyUSB0

Nice, it has detected my Huawei E220 as GSM modem, and attach it to /dev/ttyUSB0. Let’s create a wvdial configuration to connect to the telco (Celcom in my case). My /etc/wvdial.conf looks like this;

[Dialer Celcom3G]
Phone = *99***1#
Modem = /dev/ttyUSB0
Username = user
Password = pass
ISDN = 0
New PPPD = yes
Baud = 1843200
Init2 = ATZ
Init3 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Modem Type = Analog Modem

So let’s just connect;

shakir@herugrim ~ $ sudo wvdial Celcom3G
WvDial<*1>: WvDial: Internet dialer version 1.56
WvModem<*1>: Cannot get information for serial port.
WvDial<*1>: Initializing modem.
WvDial<*1>: Sending: ATZ
WvDial<*1>: Sending: ATQ0
WvDial<*1>: Re-Sending: ATZ
WvDial: Modem not responding.

Ouch, an error. The modem has been detected, what could go wrong? After some time, and no success with the available tutorials, I finally got this working, as the problem was related to the USB drivers. What I did was to reload the uhci_hcd module

shakir@herugrim ~ $ sudo modprobe -r uhci_hcd

Lets take a look at what the kernel says about this;

[..snipped..]
Dec  4 22:45:24 herugrim kernel: [ 1343.504000] usb 3-1: USB disconnect, address 6
Dec  4 22:45:24 herugrim kernel: [ 1343.504000] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
Dec  4 22:45:24 herugrim kernel: [ 1343.504000] option 3-1:1.0: device disconnected
[..snipped..]

and then lets load the module back again

shakir@herugrim ~ $ sudo modprobe uhci_hcd

and see what happens;

USB Universal Host Controller Interface driver v3.0
ACPI: PCI Interrupt 0000:00:1a.0[A
uhci_hcd 0000:00:1a.0: UHCI Host Controller
[..snipped..]
usb 3-1: new full speed USB device using uhci_hcd and address 2
usb 3-1: configuration #1 chosen from 1 choice
option 3-1:1.0: GSM modem (1-port) converter detected
usb 3-1: GSM modem (1-port) converter now attached to ttyUSB0
option 3-1:1.1: GSM modem (1-port) converter detected
usb 3-1: GSM modem (1-port) converter now attached to ttyUSB1
option 3-1:1.2: GSM modem (1-port) converter detected
usb 3-1: GSM modem (1-port) converter now attached to ttyUSB2
[..snipped..]

Last time the GSM modem was attached to just /dev/ttyUSB0, but now it’s also attached to /dev/ttyUSB1 and /dev/ttyUSB2. And I guess it’s time to connect using wvdial;

WvDial<*1>: WvDial: Internet dialer version 1.56
WvModem<*1>: Cannot get information for serial port.
WvDial<*1>: Initializing modem.
WvDial<*1>: Sending: ATZ
WvDial Modem<*1>: ATZ
WvDial Modem<*1>: OK
WvDial<*1>: Sending: ATZ
WvDial Modem<*1>: ATZ
WvDial Modem<*1>: OK
WvDial<*1>: Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
WvDial Modem<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
WvDial Modem<*1>: OK
WvDial<*1>: Modem initialized.
WvDial<*1>: Sending: ATDT*99***1#
WvDial<*1>: Waiting for carrier.
WvDial Modem<*1>: ATDT*99***1#
WvDial Modem<*1>: CONNECT
WvDial<*1>: Carrier detected.  Waiting for prompt.
WvDial: Don't know what to do!  Starting pppd and hoping for the best.
WvDial: Starting pppd at Tue Dec  4 22:49:25 2007
WvDial: Pid of pppd: 6433
WvDial<*1>: Using interface ppp0
WvDial<*1>: local  IP address 10.188.15.175
WvDial<*1>: remote IP address 10.64.64.64
WvDial<*1>: primary   DNS address 202.188.0.133
WvDial<*1>: secondary DNS address 202.188.1.5

It works, yeay As usual, lets create a script for this;

#!/bin/bash

sudo modprobe -r uhci_hcd
sudo modprobe uhci_hcd

echo "Waiting kernel to detect modem device"

# Wait till the kernel recognizes our E220
while true; do

        # Read log
        tail -n 20 /var/log/messages  > access.history
        sleep 1
        tail -n 20 /var/log/messages  > access.current

        LOG=`diff access.history access.current | grep ">" | tr -d ">"`

        # Check if it is detected
        if [[ "$LOG" =~ "converter now attached to ttyUSB1" ]]; then
                echo "Modem device detected, dialing..."
                # If it is, get out of the loop immedietly
                break
        fi
done

rm access.history access.current

# Start dialing
sudo wvdial Celcom3G

p/s: The script is now maintained here. Please go there to see the latest updates and discussions