Power Management and ACPI

(!) 2007-10-28 updated this page because stuff has become a lot easier with etch final release. (!)

Most of this works out-of-the-box. this page on the Samsung X20 (in German) has many good hints, too. 0% bightness, i.e. dark. It can be reactivated with the Kbd brightness keys.

Suspend-to-RAM works with the ati and fglrx VGA drivers. With fglrx, the display after resume is at

The battery lifetime numbers Samsung publishes (6h) are marketing exaggerations. The normal battery in my notebook lasts about 2h when I'm working normally.

You can control almost all relevant power-saving features through the excellent laptop-mode-tools package. /etc/laptop-mode/laptop-mode.conf. With cryptsetup, even suspend-on-encyrpted-swap is working nicely. I use the laptop-mode-tools option ASSUME_SCSI_IS_SATA=1 for my hard drive, and it appears to work.

ACPI buttons (power, sleep, lid)

Both the power and sleep buttons work as expected (you can control their actions through /etc/default/acpi-support).

The LID button behaves a bit weirdly though. After boot it always shows "state: closed". When I actually close the lid, keep it closed for about 20s, and reopen it, the state switches to "open". After that, the switch works, but there seems to be a 15s delay between the time I close the lid and the related ACPI event. There is no delay when the lid is opened. This is probably a BIOS issue.