Re: Disabling gpe18 at reboot

[Joe Riel <joer@san.rr.com>]

David Guntner <davidg@akaMail.net> writes:

> Joe Riel grabbed a keyboard and wrote:
>> Following an upgrade to Wheezy, my Lenovo Y560p laptop
>> showed 80% cpu usage on one core.  This was due to 
>> constant interrupts on gpe18, see, udoremember.blogspot.com.
>> 
>> I can stop this by executing
>> 
>> sudo echo disable > /sys/firmware/acpi/interrupts/gpe18
>> 
>> I'd like to have that executed at reboot.  To do so,
>> I added the following cron file:
>> 
>> # /etc/cron.d/30-disable-gpe18
>> @reboot root echo disable > /sys/firmware/acpi/interrupts/gpe18
>> 
>> Alas, that does not work.  I've verified that the line is executed,
>> however, the interrupt is not disabled.  Any ideas why that would
>> be the case?  
>
> Possibly a timing issue?  Maybe the disable command you're running takes
> effect *before* it's actually active, so it ends up running anyway?
> (I.E., it goes active after you've tried to disable it.)
>
> Try moving the command to /etc/rc.local (which runs after all the other
> init stuff has completed), and see if that helps.  The things in
> rc.local run as root as part of the startup, so you won't need the sudo.

Thanks for the suggestion, alas, it isn't helping.  I removed the cron
file and added a line to rc.local to call the following script:

#!/bin/bash

INTERRUPT=/sys/firmware/acpi/interrupts/gpe18
LOG=/home/joe/disable-gpe18.log

(   cat $INTERRUPT > $LOG
    echo clear > $INTERRUPT
    echo disable > $INTERRUPT
    cat $INTERRUPT >> $LOG
) 2>> $LOG

After rebooting, I verified that the LOG file is written.  It contains

 1556129   enabled
 1556180   enabled

The second line should end with "disabled".  If I manually execute 
the script with sudo, the log file contains

38085949   enabled
38085966   disabled

-- 
Joe Riel.