1*151f4e2bSMauro Carvalho Chehab============ 2*151f4e2bSMauro Carvalho ChehabAPM or ACPI? 3*151f4e2bSMauro Carvalho Chehab============ 4*151f4e2bSMauro Carvalho Chehab 5*151f4e2bSMauro Carvalho ChehabIf you have a relatively recent x86 mobile, desktop, or server system, 6*151f4e2bSMauro Carvalho Chehabodds are it supports either Advanced Power Management (APM) or 7*151f4e2bSMauro Carvalho ChehabAdvanced Configuration and Power Interface (ACPI). ACPI is the newer 8*151f4e2bSMauro Carvalho Chehabof the two technologies and puts power management in the hands of the 9*151f4e2bSMauro Carvalho Chehaboperating system, allowing for more intelligent power management than 10*151f4e2bSMauro Carvalho Chehabis possible with BIOS controlled APM. 11*151f4e2bSMauro Carvalho Chehab 12*151f4e2bSMauro Carvalho ChehabThe best way to determine which, if either, your system supports is to 13*151f4e2bSMauro Carvalho Chehabbuild a kernel with both ACPI and APM enabled (as of 2.3.x ACPI is 14*151f4e2bSMauro Carvalho Chehabenabled by default). If a working ACPI implementation is found, the 15*151f4e2bSMauro Carvalho ChehabACPI driver will override and disable APM, otherwise the APM driver 16*151f4e2bSMauro Carvalho Chehabwill be used. 17*151f4e2bSMauro Carvalho Chehab 18*151f4e2bSMauro Carvalho ChehabNo, sorry, you cannot have both ACPI and APM enabled and running at 19*151f4e2bSMauro Carvalho Chehabonce. Some people with broken ACPI or broken APM implementations 20*151f4e2bSMauro Carvalho Chehabwould like to use both to get a full set of working features, but you 21*151f4e2bSMauro Carvalho Chehabsimply cannot mix and match the two. Only one power management 22*151f4e2bSMauro Carvalho Chehabinterface can be in control of the machine at once. Think about it.. 23*151f4e2bSMauro Carvalho Chehab 24*151f4e2bSMauro Carvalho ChehabUser-space Daemons 25*151f4e2bSMauro Carvalho Chehab------------------ 26*151f4e2bSMauro Carvalho ChehabBoth APM and ACPI rely on user-space daemons, apmd and acpid 27*151f4e2bSMauro Carvalho Chehabrespectively, to be completely functional. Obtain both of these 28*151f4e2bSMauro Carvalho Chehabdaemons from your Linux distribution or from the Internet (see below) 29*151f4e2bSMauro Carvalho Chehaband be sure that they are started sometime in the system boot process. 30*151f4e2bSMauro Carvalho ChehabGo ahead and start both. If ACPI or APM is not available on your 31*151f4e2bSMauro Carvalho Chehabsystem the associated daemon will exit gracefully. 32*151f4e2bSMauro Carvalho Chehab 33*151f4e2bSMauro Carvalho Chehab ===== ======================================= 34*151f4e2bSMauro Carvalho Chehab apmd http://ftp.debian.org/pool/main/a/apmd/ 35*151f4e2bSMauro Carvalho Chehab acpid http://acpid.sf.net/ 36*151f4e2bSMauro Carvalho Chehab ===== ======================================= 37