How to make use of Power Management features
Contents
APM
general
You need to enable the APM Power Management support in the kernel and install the apmd to handle the events triggered by the kernel driver. The configuration for what to do at the different events is done in the proxy script which is usually found in /etc/apmd_proxy. See man apmd for further information on this.
Screen blanking (Standby)
Todo...
Suspend to RAM (Sleep)
Todo...
Suspend to disk (Hibernate)
The Phoenix BIOS allows you two ways to hibernate with APM: using a special partition or using a hibernation file on a dos type partition.
using a hibernation partition
Todo...
using a hibernation file on a dos partition
The partition to put the file on must be a dos or vfat partition. Fat32 formatted partitions have been reported successful as well as Fat16 formatted ones. The file is either created with phdisk.exe, if you happen to have a floppy drive and a bootable dos floppy disk that you can start it from. Under Linux tphdisk will do this job for you.
Todo... (how to create the file, partition size)
ACPI
general
Todo...
Screen blanking (Standby)
Todo...
Suspend to RAM (Sleep)
ACPI Sleep and suspend-to-ram with recent 2.6.x kernels usually works fine, too.
Todo...
Suspend to disk (Hibernate)
There are two drivers for this available:
- swsusp, which is in the kernel and
- SoftwareSuspend2 which is more feature rich, but not yet in the kernel, so you have to patch it in yourself
Both are reported to work fine as long as you use open-source graphic drivers. A comparison of the features can be found on this page.
using swsusp
Todo...
using SoftwareSuspend2
Todo...
Dynamic Frequency Scaling (SpeedStep)
configuring the kernel
2.4 kernels
Todo...
2.6 kernels
Todo...
If you have a Coppermine-piix-smi based Thinkpads like from the A2x, X2x and T2x series you might want to look at this page.
configuring SpeedStep daemons
Harddisk Power Management
Todo...
enabling the harddisks power management features
Todo...
Laptop-mode
Todo...
other Hardware
Todo...(if any - other ways of saving power and such)
