projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 40b4ac33 RW |
1 | APM or ACPI? |
| 2 | ------------ | |
| 3 | If you have a relatively recent x86 mobile, desktop, or server system, | |
| 4 | odds are it supports either Advanced Power Management (APM) or | |
| 5 | Advanced Configuration and Power Interface (ACPI). ACPI is the newer | |
| 6 | of the two technologies and puts power management in the hands of the | |
| 7 | operating system, allowing for more intelligent power management than | |
| 8 | is possible with BIOS controlled APM. | |
| 9 | ||
| 10 | The best way to determine which, if either, your system supports is to | |
| 11 | build a kernel with both ACPI and APM enabled (as of 2.3.x ACPI is | |
| 12 | enabled by default). If a working ACPI implementation is found, the | |
| 13 | ACPI driver will override and disable APM, otherwise the APM driver | |
| 14 | will be used. | |
| 15 | ||
| 16 | No, sorry, you cannot have both ACPI and APM enabled and running at | |
| 17 | once. Some people with broken ACPI or broken APM implementations | |
| 18 | would like to use both to get a full set of working features, but you | |
| 19 | simply cannot mix and match the two. Only one power management | |
| 20 | interface can be in control of the machine at once. Think about it.. | |
| 21 | ||
| 22 | User-space Daemons | |
| 23 | ------------------ | |
| 24 | Both APM and ACPI rely on user-space daemons, apmd and acpid | |
| 25 | respectively, to be completely functional. Obtain both of these | |
| 26 | daemons from your Linux distribution or from the Internet (see below) | |
| 27 | and be sure that they are started sometime in the system boot process. | |
| 28 | Go ahead and start both. If ACPI or APM is not available on your | |
| 29 | system the associated daemon will exit gracefully. | |
| 30 | ||
| 0ea6e611 | 31 | apmd: http://ftp.debian.org/pool/main/a/apmd/ |
| 40b4ac33 | 32 | acpid: http://acpid.sf.net/ |