Display completely freezes when laptop lid is closed if Xfwm4 compositing is enabled

Submitted by Lorenzo S.

Assigned to Olivier Fourdan @olivier

Link to original bug (#16083)

Description

When I close and re-open the lid of my Dell Vostro 7590 (but I guess it's the same for recent XPS and Inspiron models) the display is frozen and unresponsive (except for mouse cursor). The only way I can use the desktop again, is to fire a non-graphic shell (with CTRL+ALT+F1) and run sudo service lightdm restart, which fires a new working login screen, but I will lose my previous session.

This occurs if Xfwm4 compositing is enabled. If I disable it, everything works as expected, i.e. the lock screen is shown when opening the lid, and I have to enter my password to resume my session normally.

I know it's not much info, but I'm asking for things to debug the issue. I see nothing useful in the logs. Xorg log doesn't show any errors or warnings, but only (II) entries for the non-graphic shell switch. System logs (dmesg, kern, syslog) shown nothing.

Version: 4.14.0