Arch Linux

ectospasm

Member

Registered: 2015-08-28

Posts: 303

Issue with lightdm unblanking (essentially ignoring dpms commands)

I have a problem with lightdm resetting DPMS, causing my monitors to unblank just as they're just shutting down.  This has monitor longevity and power consumption concerns.   I have created a script which executes when the sleep timeout in lightdm triggers:

# cat /etc/lightdm/lightdm.conf.d/50-dpms.conf                                                                                                                                                           

[SeatDefaults]
display-setup-script=/etc/lightdm/dpms-enable
session-setup-script=/etc/lightdm/dpms-disable

# cat /etc/lightdm/dpms-enable

#!/bin/sh
(
  sleep 10
  xset dpms 0 0 65
) &

# cat /etc/lightdm/dpms-disable

#!/bin/sh
(
  xset dpms 0 0 0
) &

The screen blanks, so I know these scripts work.  But lightdm (the GTK greeter, or something related) wakes the screen immediately back up.  I don't see anything DPMS related in /var/log/lightdm/lightdm.log or /var/log/lightdm/x-1-greeter.log.  I'll post them if it's necessary.

TIA