Re: apm

[Elizabeth Barham <lizzy@soggytrousers.net>]

daves debian <dave_arahan@yahoo.co.uk> writes:

> Am i right in thinking that I need apm compiled in the kernel to allow my 
> system to turn its own power off when i
> 
> shutdown -h now ??
> 
> All the documentation seesm to be about laptops and batt saving ? I
> run a full size system.

Yes; it's funny that you mentioned this as I wondered about this same
thing and via testing determined that it is necessary.

            [*] Power Management support
            [ ]   ACPI support
            <*>   Advanced Power Management BIOS support
            [*]     Ignore USER SUSPEND
            [ ]     Enable PM at boot time
            [ ]     Make CPU Idle calls when idle
            [ ]     Enable console blanking using APM
            [*]     RTC stores time in GMT
            [ ]     Allow interrupts during APM BIOS calls
            [*]     Use real mode APM BIOS call to power off

The "Use real mode APM BIOS call to power off" is only necessary for
some machines. If mine is not set, the kernel oops on shutdown -h.

> Secondly I am having difficulty finding documentation explaining the
> parameters I can pass to the apm module, any ideas ???

The source code itself is a pretty good place to look.

./arch/i386/kernel/apm.c

/*
 * See Documentation/Config.help for the configuration options.
 *
 * Various options can be changed at boot time as follows:
 * (We allow underscores for compatibility with the modules code)
 *      apm=on/off                      enable/disable APM
 *          [no-]allow[-_]ints          allow interrupts during BIOS calls
 *          [no-]broken[-_]psr          BIOS has a broken GetPowerStatus call
 *          [no-]realmode[-_]power[-_]off       switch to real mode before
 *                                              powering off
 *          [no-]debug                  log some debugging messages
 *          [no-]power[-_]off           power off on shutdown
 *          bounce[-_]interval=<n>      number of ticks to ignore suspend
 *                                      bounces
 *          idle[-_]threshold=<n>       System idle percentage above which to
 *                                      make APM BIOS idle calls. Set it to
 *                                      100 to disable.
 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 *                                      which the idle percentage is
 *                                      calculated.
 */

Elizabeth