Comment 0 for bug 1946987

I tried both nouveau and nvidia-340 deivers. It used to work at least by the latter one in Xubuntu 18.04, even with HWE kernel

When using the nvidia-340 driver:
$ xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 1920 x 1200, current 1920 x 1200, maximum 1920 x 1200
default connected 1920x1200+0+0 0mm x 0mm
   1920x1200 77.00*

A device is connected in HDMI and xrand does not even list the connector. When using nouveau, HDMI is listed but it shows as disconnected.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.4.0-88.99-generic 5.4.140
Uname: Linux 5.4.0-88-generic x86_64
NonfreeKernelModules: nvidia
.proc.driver.nvidia.gpus.0000.01.00.0: Error: path was not a regular file.
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 340.108 Wed Dec 11 11:06:58 PST 2019
 GCC version: gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)
.proc.driver.nvidia.warnings.fbdev:
 Your system is not currently configured to drive a VGA console
 on the primary VGA device. The NVIDIA Linux graphics driver
 requires the use of a text-mode VGA console. Use of other console
 drivers including, but not limited to, vesafb, may result in
 corruption and stability problems, and is not supported.
ApportVersion: 2.20.11-0ubuntu27.20
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: skip
CompositorRunning: None
CurrentDesktop: XFCE
Date: Wed Oct 13 16:27:00 2021
DistUpgraded: 2021-10-13 15:24:05,135 DEBUG Running PostInstallScript: '/usr/lib/ubuntu-advantage/upgrade_lts_contract.py'
DistroCodename: focal
DistroVariant: ubuntu
DkmsStatus: nvidia-340, 340.108, 5.4.0-88-generic, x86_64: installed
ExtraDebuggingInterest: Yes
GraphicsCard:
 NVIDIA Corporation G84GLM [Quadro FX 570M] [10de:040c] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company G84GLM [Quadro FX 570M] [103c:30c5]
InstallationDate: Installed on 2019-05-08 (888 days ago)
InstallationMedia: Xubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210)
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-88-generic root=UUID=dd272475-45e5-4fca-b9ab-1b1f3f3015bd ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: Upgraded to focal on 2021-10-13 (0 days ago)
dmi.bios.date: 12/01/2011
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: 68MVD Ver. F.20
dmi.board.name: 30C5
dmi.board.vendor: Hewlett-Packard
dmi.board.version: KBC Version 71.36
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvr68MVDVer.F.20:bd12/01/2011:svnHewlett-Packard:pn:pvrF.20:rvnHewlett-Packard:rn30C5:rvrKBCVersion71.36:cvnHewlett-Packard:ct10:cvr:
dmi.product.family: 103C_5336AN
dmi.product.version: F.20
dmi.sys.vendor: Hewlett-Packard
nvidia-settings:
 ERROR: Unable to load info from any available system

 ERROR: Unable to load info from any available system
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.105-3~20.04.2
version.libgl1-mesa-dri: libgl1-mesa-dri 21.0.3-0ubuntu0.3~20.04.3
version.libgl1-mesa-glx: libgl1-mesa-glx 21.0.3-0ubuntu0.3~20.04.3
version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.11-1ubuntu1~20.04.2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1