Black screen when switching the monitor on after upgrade to 18.04

[Laure]

My PC has an Nvidia G98 video card with a single monitor (HP ZR22w) connected over DisplayPort. When I turn the monitor off and switch it back on, the screen remains black. The monitor displays its "no signal" message.

This only happens while logged in, either with the default Gnome-Shell interface or without a desktop environment. More precisely, if the current console is the GUI session on tty2 when I switch the monitor on, the monitor does not receive any signal. If the current console is the Gdm login screen on tty1 or a text mode login screen on tty3, the display turns on normally.

Running xrandr shows "DP-2 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 475mm x 267mm" when the monitor is on, even when the screen remains black. It shows DP-2 as disconnected while the monitor is off.

The attached log file Xorg.1.log shows a session where I log in, then turn the monitor off and turn it back on a few seconds later. X does notice that the monitor has been turned on, yet the screen remains black.

Switching consoles after turning the monitor on does not help. To get the display back, the current console has to be something other than the logged-in console at the time the monitor is switched on. Another workaround is to run "xset dpms force off; xset dpms force on" when the screen is black after switching the monitor on.

This happens since I upgraded from Ubuntu 16.04 to 18.04.

I had assistance writing this bug report, I can only type in the terminal whatever I am told.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: xserver-xorg-video-nouveau 1:1.0.15-2
ProcVersionSignature: Ubuntu 4.15.0-54.58-generic 4.15.18
Uname: Linux 4.15.0-54-generic x86_64
.tmp.unity_support_test.0:

ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
CompizPlugins: [core,composite,opengl,compiztoolbox,decor,imgpng,gnomecompat,mousepoll,place,session,vpswitch,wall,regex,animation,move,snap,grid,fade,resize,unitymtgrabhandles,expo,ezoom,scale,workarounds,unityshell]
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Sun Jun 30 10:52:07 2019
DistUpgraded: 2019-06-29 14:02:39,816 ERROR got error from PostInstallScript ./xorg_fix_proprietary.py (g-exec-error-quark: L'exécution du processus fils « ./xorg_fix_proprietary.py » a échoué (No such file or directory) (8))
DistroCodename: bionic
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes, if not too technical
GraphicsCard:
 NVIDIA Corporation G98 [Quadro NVS 295] [10de:06fd] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: NVIDIA Corporation G98 [Quadro NVS 295] [10de:062e]
InstallationDate: Installed on 2016-10-28 (974 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
MachineType: Hewlett-Packard HP Compaq 8000 Elite CMT PC
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-54-generic root=/dev/mapper/vg1-lv_ubuntu ro quiet splash vt.handoff=1
SourcePackage: xserver-xorg-video-nouveau
UpgradeStatus: Upgraded to bionic on 2019-06-29 (0 days ago)
dmi.bios.date: 10/22/2009
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: 786G7 v01.02
dmi.board.asset.tag: CZC113CLV8
dmi.board.name: 3647h
dmi.board.vendor: Hewlett-Packard
dmi.chassis.asset.tag: CZC113CLV8
dmi.chassis.type: 6
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvr786G7v01.02:bd10/22/2009:svnHewlett-Packard:pnHPCompaq8000EliteCMTPC:pvr:rvnHewlett-Packard:rn3647h:rvr:cvnHewlett-Packard:ct6:cvr:
dmi.product.family: 103C_53307F
dmi.product.name: HP Compaq 8000 Elite CMT PC
dmi.sys.vendor: Hewlett-Packard
version.compiz: compiz 1:0.9.13.1+18.04.20180302-0ubuntu1
version.libdrm2: libdrm2 2.4.95-1~18.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 18.2.8-0ubuntu0~18.04.2
version.libgl1-mesa-glx: libgl1-mesa-glx 18.2.8-0ubuntu0~18.04.2
version.xserver-xorg-core: xserver-xorg-core 2:1.19.6-1ubuntu4.3
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.5-1ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:18.0.1-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20171229-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-2
xserver.bootTime: Sat Jun 29 11:10:16 2019
xserver.configfile: default
xserver.devices:
 input Power Button KEYBOARD, id 6
 input Power Button KEYBOARD, id 7
 input PIXART USB OPTICAL MOUSE MOUSE, id 8
 input AT Translated Set 2 keyboard KEYBOARD, id 9
 input HP WMI hotkeys KEYBOARD, id 10
xserver.errors:
 Failed to load module "nvidia" (module does not exist, 0)
 Failed to load module "nvidia" (module does not exist, 0)
xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.18.4-0ubuntu0.8
xserver.video_driver: nouveau