Documentation/power/apm-acpi.txt

2 ------------
3 If you have a relatively recent x86 mobile, desktop, or server system,
7 operating system, allowing for more intelligent power management than
10 The best way to determine which, if either, your system supports is to
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
27 and be sure that they are started sometime in the system boot process.
29 system the associated daemon will exit gracefully.
31   apmd:   http://ftp.debian.org/pool/main/a/apmd/