Running Gnome 3.28. I am having problems with screen blanking. More specifically, the screen is not blanking, and I cannot figure out how to get it to blank consistently anymore. (Sometime, years ago, I killed screen blanking completely, and no longer have any idea how I did it.) Throughout this, when I refer to blanking, I specifically want/prefer DPMS off behavior.

Setting "Blank Screen" in the "Power" section of gnome-preferences does nothing. xset q returns the following:

DPMS (Energy Star):
  Standby: 0    Suspend: 0    Off: 0
  DPMS is Enabled
  Monitor is On

I can turn on screen blanking by using xset dpms 1200 2400 4800. This works. However, running any application that uses dbus to request inhibiting screen blanking (such as Youtube in chrome) causes the gnome power settings daemon to set these values back to zero, and never sets them back.

Tracing what is happening, starting, say, Youtube, sends an inhibit request to the SessionManager:

method call time=1533650079.657788 sender=:1.1216 -> destination=org.gnome.SessionManager serial=3 path=/org/gnome/SessionManager; interface=org.gnome.SessionManager; member=Inhibit
   string "/usr/bin/google-chrome-stable"
   uint32 0
   string "Playing video"
   uint32 12
signal time=1533650079.659445 sender=:1.14 -> destination=(null destination) serial=10679 path=/org/gnome/SessionManager; interface=org.gnome.SessionManager; member=InhibitorAdded
   object path "/org/gnome/SessionManager/Inhibitor975"
method return time=1533650079.659468 sender=:1.14 -> destination=:1.1216 serial=10680 reply_serial=3
   uint32 754926118
signal time=1533650079.659475 sender=:1.14 -> destination=(null destination) serial=10681 path=/org/gnome/SessionManager; interface=org.freedesktop.DBus.Properties; member=PropertiesChanged
   string "org.gnome.SessionManager"
   array [
      dict entry(
         string "InhibitedActions"
         variant             uint32 12
   array [

This causes the gsd-power daemon to ask mutter to turn off power save mode:

method call time=1533650079.666562 sender=:1.36 -> destination=:1.16 serial=182 path=/org/gnome/Mutter/DisplayConfig; interface=org.freedesktop.DBus.Properties; member=Set
   string "org.gnome.Mutter.DisplayConfig"
   string "PowerSaveMode"
   variant       int32 0

which works, turning the DPMS settings to zeros. When I close the youtube session, I get a matching uninhibit request:

method call time=1533650081.283611 sender=:1.1216 -> destination=org.gnome.SessionManager serial=4 path=/org/gnome/SessionManager; interface=org.gnome.SessionManager; member=Uninhibit
   uint32 754926118
signal time=1533650081.286730 sender=:1.14 -> destination=(null destination) serial=10690 path=/org/gnome/SessionManager; interface=org.gnome.SessionManager; member=InhibitorRemoved
   object path "/org/gnome/SessionManager/Inhibitor975"
method call time=1533650081.286768 sender=:1.14 -> destination=org.freedesktop.DBus serial=10691 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=RemoveMatch
   string "type='signal',sender='org.freedesktop.DBus',interface='org.freedesktop.DBus',member='NameOwnerChanged',path='/org/freedesktop/DBus',arg0=':1.1216'"
method return time=1533650081.286778 sender=org.freedesktop.DBus -> destination=:1.14 serial=3032 reply_serial=10691
method return time=1533650081.286784 sender=:1.14 -> destination=:1.1216 serial=10692 reply_serial=4
signal time=1533650081.286789 sender=:1.14 -> destination=(null destination) serial=10693 path=/org/gnome/SessionManager; interface=org.freedesktop.DBus.Properties; member=PropertiesChanged
   string "org.gnome.SessionManager"
   array [
      dict entry(
         string "InhibitedActions"
         variant             uint32 4
   array [

But nothing tells mutter to turn power save mode back on. What is normally supposed to do that, and what might prevent it from doing so?


1 Answer 1


Have you got gdm turned on because without locking screen there won't be any dimming.

The isssue is gdm is reading org.gnome.SessionManager.Presence as previous gnome-scrennsaver so sending messages to mutter is fake because reset timers should be done only one time.

Diming is done by sending dpms force off or on not relying on dpms timers

cheers, RObert

  • I do not have gdm on. I moved away from gdm a few years ago when it was taking most of a CPU while I was logged in. Things might have changed since then. It seems a little bizarre that different programs would handle turning on and off dpms.
    – md5i
    Feb 19, 2019 at 13:08
  • First time mutter receive message (as you pointed out) and set dmps timeouts off and set dpms force on and next it is notified that dummy screen saver was enabled by gdm so it turns off monitor by dpms force off. So it is same program that changes off and on - mutter. Try gdm it should be fine if not comment. Maybe i could help
    – robert
    Feb 21, 2019 at 17:41

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