Regression: Kubuntu 22.04 LTS overrides Xorg.conf-specified monitor layout

[Stephan Sokolow]

When I built a new PC with Kubuntu 22.04 LTS, I carried over my recently purchased GeForce RTX 3060 and copied over the Xorg.conf that was doing perfectly well for me in 20.04 LTS, containing the following line:

Option "metamodes" "HDMI-0: 1280x1024 +3200+0, DP-3: 1280x1024 +0+0, DP-1: 1920x1080 +1280+0"

(Bear in mind that, due to a history of bugginess in KScreen2 and how it interacts with Plasma panel layouts, I disable it in the Background Services control panel and do my best to lock down the allowed layouts and resolutions in Xorg.conf.)

This technique has been working for me for close to a decade, with my previous video card being a GeForce GTX750 and, if I remember correctly, I was also using it with the GeForce GT430 I was using before that, and with Kubuntu and Lubuntu versions going back to at least Kubuntu 16.04 LTS and likely to Lubuntu 14.04 and possibly even Lubuntu 12.04.

However, much to my dismay, it appeared to have no effect, and the system was still assigning a virtual layout that didn't match the physical arrangement of the monitors.

Eventually, I realized from /var/log/Xorg.0.log that my metamodes line WAS getting set, but, for reasons I still have no idea how to diagnose, something else was overriding it and resetting the metamodes line back to the undesired default, with unlocked resolutions and an incorrect monitor layout.

[ 21.689] (II) NVIDIA(0): Setting mode "HDMI-0: 1280x1024 @1280x1024 +3200+0 {ViewPortIn=1280x1024, ViewPortOut=1280x1024+0+0}, DP-3: 1280x1024 @1280x1024 +0+0 {ViewPortIn=1280x1024, ViewPortOut=1280x1024+0+0}, DP-1: nvidia-auto-select @1920x1080 +0+0 {ViewPortIn=1920x1080, ViewPortOut=1920x1080+0+0}"
[ 21.747] (II) NVIDIA(0): Setting mode "DP-3: 1280x1024 @1280x1024 +0+0 {ViewPortIn=1280x1024, ViewPortOut=1280x1024+0+0}, DP-1: nvidia-auto-select @1920x1080 +0+0 {ViewPortIn=1920x1080, ViewPortOut=1920x1080+0+0}"
[ 21.834] (II) NVIDIA(0): Setting mode "HDMI-0: nvidia-auto-select @1280x1024 +1920+0 {ViewPortIn=1280x1024, ViewPortOut=1280x1024+0+0}, DP-3: 1280x1024 @1280x1024 +0+0 {ViewPortIn=1280x1024, ViewPortOut=1280x1024+0+0}, DP-1: nvidia-auto-select @1920x1080 +0+0 {ViewPortIn=1920x1080, ViewPortOut=1920x1080+0+0}"
[ 21.922] (II) NVIDIA(0): Setting mode "HDMI-0: nvidia-auto-select @1280x1024 +1920+0 {ViewPortIn=1280x1024, ViewPortOut=1280x1024+0+0}, DP-3: nvidia-auto-select @1280x1024 +3200+0 {ViewPortIn=1280x1024, ViewPortOut=1280x1024+0+0}, DP-1: nvidia-auto-select @1920x1080 +0+0 {ViewPortIn=1920x1080, ViewPortOut=1920x1080+0+0}"

As a workaround which may or may not show up in the ubuntu-bug report, I've created a /etc/X11/Xsession.d/01-fix-the-damn-ignored-metamodes file containing the line `xrandr --output DP-3 --left-of DP-1`.

...though that doesn't fix the monitor layout at the login screen and it's not possible to work around the forced changeability of the resolution without a working metamodes according to https://gitlab.freedesktop.org/xorg/xserver/-/issues/353#note_91110

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: xorg 1:7.7+23ubuntu2
ProcVersionSignature: Ubuntu 6.5.0-14.14~22.04.1-generic 6.5.3
Uname: Linux 6.5.0-14-generic x86_64
NonfreeKernelModules: zfs nvidia_modeset nvidia
.proc.driver.nvidia.capabilities.gpu0: Error: path was not a regular file.
.proc.driver.nvidia.capabilities.mig: Error: path was not a regular file.
.proc.driver.nvidia.gpus.0000.01.00.0: Error: path was not a regular file.
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.suspend: suspend hibernate resume
.proc.driver.nvidia.suspend_depth: default modeset uvm
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 535.146.02 Sun Dec 3 14:06:14 UTC 2023
 GCC version: gcc version 12.3.0 (Ubuntu 12.3.0-1ubuntu1~22.04)
ApportVersion: 2.20.11-0ubuntu82.5
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: pass
CompositorRunning: None
CurrentDesktop: KDE
Date: Tue Jan 30 06:25:44 2024
DistUpgraded: Fresh install
DistroCodename: jammy
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 NVIDIA Corporation GA106 [GeForce RTX 3060 Lite Hash Rate] [10de:2504] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. GA106 [GeForce RTX 3060 Lite Hash Rate] [1043:8810]
 Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:164e] (rev c6) (prog-if 00 [VGA controller])
   Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:164e]
InstallationDate: Installed on 2024-01-05 (24 days ago)
InstallationMedia: Kubuntu 22.04.3 LTS "Jammy Jellyfish" - Release amd64 (20230807.1)
MachineType: ASRock B650 PG Lightning
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.5.0-14-generic root=UUID=7aefb7ca-223b-4111-81e4-0d2a1003dbce ro zfs.zfs_dmu_offset_next_sync=0 quiet splash vt.handoff=7
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/26/2023
dmi.bios.release: 5.26
dmi.bios.vendor: American Megatrends International, LLC.
dmi.bios.version: 1.21
dmi.board.asset.tag: Default string
dmi.board.name: B650 PG Lightning
dmi.board.vendor: ASRock
dmi.board.version: Default string
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.modalias: dmi:bvnAmericanMegatrendsInternational,LLC.:bvr1.21:bd04/26/2023:br5.26:svnASRock:pnB650PGLightning:pvrDefaultstring:rvnASRock:rnB650PGLightning:rvrDefaultstring:cvnDefaultstring:ct3:cvrDefaultstring:skuDefaultstring:
dmi.product.family: Default string
dmi.product.name: B650 PG Lightning
dmi.product.sku: Default string
dmi.product.version: Default string
dmi.sys.vendor: ASRock
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.113-2~ubuntu0.22.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 23.0.4-0ubuntu1~22.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A
version.xserver-xorg-core: xserver-xorg-core 2:21.1.4-2ubuntu1.7~22.04.7
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-2ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20210115-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.17-2build1