[CLUE-Tech] ACPI Working (laptop owners take note)

[Matt Gushee]

This might be of interest to those who have laptops and have had trouble
with APM (and who hasn't?):

In the course of my never-ending quest to get and keep sound working on
my %&#*(@)##)@)+ Dell laptop, I stumbled across a mailing list message
advising someone to build their kernel with ACPI instead of APM, so I
decided to try it.

  [ ACPI is the modern replacement for APM. Most if not all recent
    laptops have ACPI ]

It wasn't easy, but I now have ACPI support under Linux. I should
emphasize that the drivers are still a work in progress, and they
don't yet support all ACPI features (e.g. there's no sleep/suspend
functionality yet). But I like the fact that what it does, it seems to
do quite well. For example, I can now hit the power button and have the
OS shut down cleanly before the power goes off. The 'acpi' client
program gives what seems to be correct information about battery status,
and will also report the CPU temperature. Coolness!

Briefly, here's what I did:

  1. Got the 2.4.22 kernel source from ftp.kernel.org.
     (The kernel source packages from RedHat/Debian/etc. are
      usually patched, which makes the next steps problematic)
  2. Got the ACPI patch for kernel 2.4.22 from the ACPI4Linux
     project (acpi.sourceforge.net).
  3. Applied the patch.
  4. Enabled ACPI support in the kernel config (built into the
     kernel--you can build it as a module, but I've seen info to
     the effect that that's a bad idea).
  5. Compiled, installed, etc.
  6. Installed the acpid (daemon) and acpi (client) packages.

Voila!

There is also a thing called DSDT, which is a way of customizing the
driver for a specific machine. I didn't do that because there was no
DSDT file available for my box (Dell Inspiron 3500), but my kernel seems
to work fine anyway.

Of course, all the usual precautions apply: back up your data, keep your
present kernel available, YMMV ...

Anyway, ACPI may be worth a try. For more details, see the documentation
at acpi.sourceforge.net.

-- 
Matt Gushee                 When a nation follows the Way,
Englewood, Colorado, USA    Horses bear manure through
mgushee at havenrock.com           its fields;
http://www.havenrock.com/   When a nation ignores the Way,
                            Horses bear soldiers through
                                its streets.
                                
                            --Lao Tzu (Peter Merel, trans.)