I’ve been having an issue with my laptop waking up from sleep after I’ve closed the lid to send it into suspend. This would drain battery and overheat the laptop, especially when placed into a backpack or bag! Very frustrating to get to wherever you’re going and realize that your laptop is dead.
It’s a Macbook Pro from 2015, and it’s running Ubuntu 18.10.
After investigating what was happening via
/var/log/syslog examination, I found a number of errors happening due to ARP table lookups. I spent a while trying to fix that, but eventually settled on a solution that just disabled wake-over-WiFi.
I checked what was able to wake up the device with:
Which displayed a table that looked like this:
Device S-state Status Sysfs node PEG0 S3 *disabled pci:0000:00:01.0 PEG1 S3 *disabled pci:0000:00:01.1 PEG2 S3 *disabled ARPT S4 *enabled pci:0000:03:00.0 RP04 S3 *disabled pci:0000:00:1c.3 XHC1 S3 *enabled pci:0000:00:14.0 ADP1 S4 *disabled platform:ACPI0003:00 LID0 S4 *enabled platform:PNP0C0D:00
After some digging in
/var/log/syslog, I found out that there were a number of wakeups happening because of ARP table issues. I had a hunch that the
ARPT device was linked to that, and disabled it by creating a
/etc/rc.local file. This file runs every time the computer boots, and mine looks like this:
#! /bin/sh echo ARPT > /proc/acpi/wakeup
Don’t forget to make it executable via a
chmod +x /etc/rc.local!