[Bug 2060268] Re: Phantom "Unknown Display" shown in Settings after installing the Nvidia driver

Isn't this also a Gnome settings bug? Even with the presence of an
erroneously detected extra monitor, shouldn't we be able to simply
deactivate it / configure the desktop to not span across both monitors?

The Settings > Displays GUI doesn't seem to work correctly. The
"Unknown" monitor is reported as being inactive, although we can see the
effects of e.g. the mouse pointer getting lost on the right.
Activating/deactivating the "Unknown" monitor also doesn't work.

--
You received this bug notification because you are subscribed to linux
in Ubuntu.
Matching subscriptions: Bgg, Bmail, Nb
https://bugs.launchpad.net/bugs/2060268

Title:
Phantom "Unknown Display" shown in Settings after installing the
Nvidia driver

Status in linux package in Ubuntu:
Confirmed
Status in nvidia-graphics-drivers-470 package in Ubuntu:
Confirmed
Status in nvidia-graphics-drivers-535 package in Ubuntu:
Confirmed
Status in nvidia-graphics-drivers-545 package in Ubuntu:
Confirmed
Status in nvidia-graphics-drivers-550 package in Ubuntu:
Confirmed

Bug description:
[ Impact ]

After installing Nvidia driver 545 on a single (27") monitor system,
Settings shows a phantom 46" monitor of the same resolution.

It looks like the phantom monitor is /dev/dri/card0 which is still
controlled by simpledrm, while Nvidia uses /dev/dri/card1.

[ Workaround ]

1. sudo rm /dev/dri/card0
2. Log in again.

[ Test Plan ]

Open Settings and verify the only monitors shown are your real
monitors.

[ Where problems could occur ]

Removing the simpledrm card is only safe when it's not being used. If
somehow a machine wasn't using the installed Nvidia driver then there
could be a risk of deleting the only working display.

[ Other Info ]

ProblemType: Bug
ApportVersion: 2.28.0-0ubuntu1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/seq: dan 4631 F.... pipewire
 /dev/snd/controlC1: dan 4636 F.... wireplumber
CRDA: N/A
CasperMD5CheckResult: pass
DistroRelease: Ubuntu 24.04
InstallationDate: Installed on 2024-01-04 (92 days ago)
InstallationMedia: Ubuntu 24.04 "Noble Numbat" - Daily amd64 (20231127)
MachineType: Intel(R) Client Systems NUC12DCMi7
NonfreeKernelModules: nvidia_modeset nvidia
Package: linux (not installed)
ProcEnviron:
 LANG=en_US.UTF-8
 PATH=(custom, no user)
 SHELL=/bin/bash
 TERM=xterm-256color
 XDG_RUNTIME_DIR=<set>
ProcFB: 0 simpledrmdrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.8.0-11-generic root=UUID=8434774e-88f2-4e3f-adb8-2eb07dff3cf9 ro quiet loglevel=3 splash vt.handoff=7
ProcVersionSignature: Ubuntu 6.8.0-11.11-generic 6.8.0-rc4
RelatedPackageVersions:
 linux-restricted-modules-6.8.0-11-generic N/A
 linux-backports-modules-6.8.0-11-generic N/A
 linux-firmware 20240318.git3b128b60-0ubuntu1
Tags: noble
Uname: Linux 6.8.0-11-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sudo users
_MarkForUpload: True
dmi.bios.date: 12/20/2021
dmi.bios.release: 5.24
dmi.bios.vendor: Intel Corp.
dmi.bios.version: EDADL579.0046.2021.1220.2351
dmi.board.name: NUC12EDBi7
dmi.board.vendor: Intel Corporation
dmi.board.version: M27908-302
dmi.chassis.type: 35
dmi.chassis.vendor: Intel Corporation
dmi.chassis.version: 2.0
dmi.ec.firmware.release: 3.7
dmi.modalias: dmi:bvnIntelCorp.:bvrEDADL579.0046.2021.1220.2351:bd12/20/2021:br5.24:efr3.7:svnIntel(R)ClientSystems:pnNUC12DCMi7:pvrM30143-302:rvnIntelCorporation:rnNUC12EDBi7:rvrM27908-302:cvnIntelCorporation:ct35:cvr2.0:skuRNUC12DCMi70000:
dmi.product.family: DC
dmi.product.name: NUC12DCMi7
dmi.product.sku: RNUC12DCMi70000
dmi.product.version: M30143-302
dmi.sys.vendor: Intel(R) Client Systems

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2060268/+subscriptions