Bug#894306: gnome-control-center: gnome display external monitor resolution higher than full hd freezes the system: only in 3.28

[Simon McVittie]

Control: tags -1 + moreinfo

On Wed, 28 Mar 2018 at 19:22:41 +0200, geodeb wrote:
> until gnome 3.26 it was correctly detected. now it works
> only on full hd resolution. higher resolutions cause the blackout of both the
> displays and the only way out is to power off.

This is not a bug in gnome-control-center: that component only changes
configuration, and isn't responsible for the actual modesetting. I'd
reassign it to another package, but I don't yet know which package would
be most appropriate (candidates include gnome-shell, libmutter-2-0,
libdrm* and the Linux kernel).

The package information from "reportbug --template libglx-mesa0"
and "reportbug --template gnome-shell" would be very useful information:
that would tell us about your gnome-shell, mutter and graphics driver
versions.

What graphics hardware does this machine have? (NVIDIA? AMD? Intel?)

Please look in /var/log/syslog for log messages from gnome-shell shortly
before the power-off. I would guess that you might see something similar
to the logs quoted on these upstream bug reports:
https://gitlab.gnome.org/GNOME/gnome-shell/issues/153
https://gitlab.gnome.org/GNOME/mutter/issues/93
https://gitlab.gnome.org/GNOME/mutter/issues/81

When the system is in this state (with both displays blank), does it
still respond to network connections (ping, ssh)?

If you have a Caps Lock, Num Lock or Scroll Lock LED on your keyboard,
does pressing those keys still toggle the appropriate LED?

If you type Ctrl+Alt+F6, do you see a text-mode login prompt?

If not, if you type Ctrl+Alt+F6 (even if it has no visible effect)
followed by Ctrl+Alt+Del, does the machine reboot? If it does, what do
you see while it's rebooting?

Thanks,
    smcv