Today I notice some strange behavior of my laptop since all hotkeys did not show on-screen display anymore. All buttons still work as expect but Gnome don't get notification so mute/unmute will not effect the icon in notification area. It seems to just happer after upgrading kernel to 2.6.22-11. Well, I have found workaround.

What I did is just to add below line to /etc/modules to force loading of thinkpad_acpi module.

thinkpad_acpi

As a plus, you may modify /etc/modprobe.d/thinkpad_acpi.modprobe to enable fan control.

options thinkpad_acpi hotkey=enable,0xffff8f experimental=1 fan_control=1

After reload this module, you will be able to control your fan.

echo level 0 > /proc/acpi/ibm/fan
echo level auto > /proc/acpi/ibm/fan

The default fan speed is auto.

Tags: ibm, thinkpad, ubuntu, gutsy gibbon, acpi