| Mauro Carvalho Chehab | 151f4e2 | 2019-06-13 07:10:36 -0300 | [diff] [blame] | 1 | ============ |
| Rafael J. Wysocki | 40b4ac3 | 2008-07-23 21:28:36 -0700 | [diff] [blame] | 2 | APM or ACPI? |
| Mauro Carvalho Chehab | 151f4e2 | 2019-06-13 07:10:36 -0300 | [diff] [blame] | 3 | ============ |
| 4 | |
| Rafael J. Wysocki | 40b4ac3 | 2008-07-23 21:28:36 -0700 | [diff] [blame] | 5 | If you have a relatively recent x86 mobile, desktop, or server system, |
| 6 | odds are it supports either Advanced Power Management (APM) or |
| 7 | Advanced Configuration and Power Interface (ACPI). ACPI is the newer |
| 8 | of the two technologies and puts power management in the hands of the |
| 9 | operating system, allowing for more intelligent power management than |
| 10 | is possible with BIOS controlled APM. |
| 11 | |
| 12 | The best way to determine which, if either, your system supports is to |
| 13 | build a kernel with both ACPI and APM enabled (as of 2.3.x ACPI is |
| 14 | enabled by default). If a working ACPI implementation is found, the |
| 15 | ACPI driver will override and disable APM, otherwise the APM driver |
| 16 | will be used. |
| 17 | |
| 18 | No, sorry, you cannot have both ACPI and APM enabled and running at |
| 19 | once. Some people with broken ACPI or broken APM implementations |
| 20 | would like to use both to get a full set of working features, but you |
| 21 | simply cannot mix and match the two. Only one power management |
| 22 | interface can be in control of the machine at once. Think about it.. |
| 23 | |
| 24 | User-space Daemons |
| 25 | ------------------ |
| 26 | Both APM and ACPI rely on user-space daemons, apmd and acpid |
| 27 | respectively, to be completely functional. Obtain both of these |
| 28 | daemons from your Linux distribution or from the Internet (see below) |
| 29 | and be sure that they are started sometime in the system boot process. |
| 30 | Go ahead and start both. If ACPI or APM is not available on your |
| 31 | system the associated daemon will exit gracefully. |
| 32 | |
| Mauro Carvalho Chehab | 151f4e2 | 2019-06-13 07:10:36 -0300 | [diff] [blame] | 33 | ===== ======================================= |
| 34 | apmd http://ftp.debian.org/pool/main/a/apmd/ |
| 35 | acpid http://acpid.sf.net/ |
| 36 | ===== ======================================= |