Ubuntu
light-locker package

  1. Bug #1759950
  2. Comment #15

Comment 15 for bug 1759950

Revision history for this message
TJ (tj) wrote :

Yet more results changing the target once again!

I was able to reproduce the issue whilst using sddm which tends to suggest lightdm may not be the cause.

I also managed to prove (not sure why this did not occur to me before now!) that the DPMS state is being set 'off' when switching to the GUI tty and 'on' when switching away.

In a console TTY I had:

$ while true; do grep . /sys/class/drm/card0-LVDS-1/{dpms,enabled,status}; sleep 1; done

And then switched to the GUI and closed the lid. After resuming from suspend and unlocking the GUI blanked. Switching to the console TTY showed that whilst on the GUI TTY

dpms=off

which changes to

dpms=on

when switching away from it.

This tends to point pack towards xfce4-power-manager and upower since, as I currently understand it, they specifically 'do' DPMS 'stuff'.

Certainly x-p-m has a lot of DPMS handling code and user-config properties exposed.