FC3: Power Management on Sharp MM20

[Frank]

Years ago I was comfy with *nix, but that was years ago and much has 
changed.  I've recently switched my laptop from Windows to FC3 as part 
of a plan to reverse the trend.  It's been a rough ride.

Sound isn't working, but that's not a high priority for me.  Power 
management isn't working, and that really matters a lot.  I need to slow 
down the processor when I'm on battery or my battery life sucks.

I have acpid recognizing the AC_adaptor events, and I'm running the 
following script (borrowed from somewhere and modified to add debug info.)

------
CPUNODE=/dev/cpu/0
LOGFILE=/var/log/acpid
MYNAME=$0

_log()
{
        echo "[`date`]" $MYNAME $* >> $LOGFILE
}

_cmd()
{
        $* || (_log COMMAND FAILED: $*;exit 1)
}

_log $*

if [ ! -d $CPUNODE ]; then
        _cmd mkdir /dev/cpu
        _cmd mkdir /dev/cpu/0
fi

if [ ! -c /dev/cpu/0/cpuid ]; then
        _cmd mknod /dev/cpu/0/cpuid c 203 0
fi

if [ ! -c /dev/cpu/0/msr ]; then
        _cmd mknod /dev/cpu/0/msr c 202 0
fi

case "$4" in
        00000001)
                #echo "brightness: 7" > /proc/acpi/toshiba/lcd
                _cmd longrun -f performance
                _cmd longrun -s 0 100
        ;;
        00000000)
                #echo brightness: 1 > /proc/acpi/toshiba/lcd
                _cmd longrun -f economy
                _cmd longrun -s 0 0
        ;;
        *)
                echo "Usage: ac [00000000|00000001]"
                exit 1
esac

exit 0
---------
Here's what I see in /var/log/acpid when I unplug the adapter and plug 
it back in:

[Wed Nov 17 19:15:32 2004] received event "ac_adapter AC 00000080 00000000"
[Wed Nov 17 19:15:32 2004] notifying client 3616[500:500]
[Wed Nov 17 19:15:32 2004] executing action "/etc/acpi/ac_adaptor 
ac_adapter AC 00000080 00000000"
[Wed Nov 17 19:15:32 2004] BEGIN HANDLER MESSAGES
[Wed Nov 17 19:15:33 EST 2004] /etc/acpi/ac_adaptor ac_adapter AC 
00000080 00000000
longrun: error opening /dev/cpu/0/cpuid: No such device or address
[Wed Nov 17 19:15:33 EST 2004] /etc/acpi/ac_adaptor COMMAND FAILED: 
longrun -f economy
longrun: error opening /dev/cpu/0/cpuid: No such device or address
[Wed Nov 17 19:15:33 EST 2004] /etc/acpi/ac_adaptor COMMAND FAILED: 
longrun -s 0 0
[Wed Nov 17 19:15:33 2004] END HANDLER MESSAGES
[Wed Nov 17 19:15:33 2004] action exited with status 0
[Wed Nov 17 19:15:33 2004] completed event "ac_adapter AC 00000080 00000000"
[Wed Nov 17 19:15:35 2004] received event "ac_adapter AC 00000080 00000001"
[Wed Nov 17 19:15:35 2004] notifying client 3616[500:500]
[Wed Nov 17 19:15:35 2004] executing action "/etc/acpi/ac_adaptor 
ac_adapter AC 00000080 00000001"
[Wed Nov 17 19:15:35 2004] BEGIN HANDLER MESSAGES
[Wed Nov 17 19:15:35 EST 2004] /etc/acpi/ac_adaptor ac_adapter AC 
00000080 00000001
longrun: error opening /dev/cpu/0/cpuid: No such device or address
[Wed Nov 17 19:15:35 EST 2004] /etc/acpi/ac_adaptor COMMAND FAILED: 
longrun -f performance
longrun: error opening /dev/cpu/0/cpuid: No such device or address
[Wed Nov 17 19:15:35 EST 2004] /etc/acpi/ac_adaptor COMMAND FAILED: 
longrun -s 0 100
[Wed Nov 17 19:15:35 2004] END HANDLER MESSAGES
[Wed Nov 17 19:15:35 2004] action exited with status 0
[Wed Nov 17 19:15:35 2004] completed event "ac_adapter AC 00000080 00000001"

The device node in question does exist, but I get the same "No device or 
address" error if I try to cat it.  What more do I need to do to make 
this work?

And a related question:

If I cat /proc/cpuinfo and it tells me a certain speed, is that the 
maximum speed of the processor or the current speed?

I hope somebody can help.   I've been googling and wrestling with this 
for a week now.

Frank.