"Ghost" monitor (Cinnamon beta)

[MiZoG99]

Mint 22 Cinnamon beta: A "ghost monitor" appears in my system.

  Monitor-1: HDMI-A-1 mapped: HDMI-0 note: disabled pos: primary
    model: AOC 24E1W1 serial: PPCP1HA001165 built: 2023 res: 1920x1080 hz: 60
    dpi: 93 gamma: 1.2 size: 527x296mm (20.75x11.65") diag: 604mm (23.8")
    ratio: 16:9 modes: max: 1920x1080 min: 640x480
  Monitor-2: Unknown-1 mapped: None-1-1 note: disabled size-res: N/A
    modes: 1024x768

Full system specs (inxi)

xrandr output

Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384
VGA-0 disconnected (normal left inverted right x axis y axis)
DVI-D-0 disconnected (normal left inverted right x axis y axis)
HDMI-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 527mm x 296mm
   1920x1080     60.00*+  59.94    50.00    60.00    50.04  
   1680x1050     59.95  
   1440x900      59.89  
   1280x1024     75.02    60.02  
   1280x960      60.00  
   1280x720      60.00    59.94    50.00  
   1024x768      75.03    70.07    60.00  
   800x600       75.00    72.19    60.32    56.25  
   720x576       50.00  
   720x480       59.94  
   640x480       75.00    72.81    59.94    59.93  
None-1-1 connected (normal left inverted right x axis y axis)
   1024x768      60.00 +

Integrated intel graphics is disabled in UEFI/Bios settings.

"Real" monitor in Display Settings

Ghost monitor in Display Settings

Slight buggy behaviour results from this. A screenshot taken assumes my screen size comprises both the real and imaginary monitors:

Occurrences of screen tearing not present in previous Cinnamon builds are perhaps related to this bug. This is just an assumption though.

Most interestingly this "ghost" monitor is not present upstream. Current Ubuntu 24.04, same base system, same hardware, same nvidia driver version, same X server:

Suffice to say this was neither present in Cinnamon 6.0.4 in both Mint 21.3 / LMDE 6

[JosephMcc]

Did you happen to restart Cinnamon before this showed up? Doesn't happen to me on first boot, only after a Cinnamon restart.

[MiZoG99]

I didn't notice it early to say when it did appear for a first time.

[Harry-W-Haines-III]

I noticed the same thing myself but I'm not sure its related to Cinnamon. It looks like it has something to do with the NVIDIA driver and kernel. Take a look at this:

nvidia with nouveau driver:

inxi -Gxxx Graphics: Device-1: NVIDIA GA107 [GeForce RTX 3050 6GB] vendor: Micro-Star MSI driver: nouveau v: kernel arch: Ampere ports: active: DP-1 empty: HDMI-A-1,HDMI-A-2 bus-ID: 0000:01:00.0 chip-ID: 10de:2584 class-ID: 0300 Display: x11 server: X.Org v: 21.1.11 with: Xwayland v: 23.2.6 driver: X: loaded: modesetting unloaded: fbdev,vesa dri: nouveau gpu: nouveau display-ID: :0 screens: 1 Screen-1: 0 s-res: 2560x1440 s-dpi: 96 s-size: 677x381mm (26.65x15.00") s-diag: 777mm (30.58") Monitor-1: DP-1 model: HP OMEN 32q serial: CNC4140L69 res: 2560x1440 hz: 60 dpi: 93 size: 697x393mm (27.44x15.47") diag: 800mm (31.5") modes: max: 2560x1440 min: 720x400 API: EGL v: 1.5 hw: drv: nvidia nouveau platforms: device: 0 drv: nouveau device: 1 drv: swrast gbm: drv: nouveau surfaceless: drv: nouveau x11: drv: nouveau inactive: wayland API: OpenGL v: 4.5 compat-v: 4.3 vendor: mesa v: 24.0.5-1ubuntu1 glx-v: 1.4 direct-render: yes renderer: NV177 device-ID: 10de:2584

nvidia with driver: nvidia v: 535.183.01 (current general release version)

inxi -Gxxx Graphics: Device-1: NVIDIA GA107 [GeForce RTX 3050 6GB] vendor: Micro-Star MSI driver: nvidia v: 535.183.01 arch: Ampere ports: active: none off: DP-1 empty: HDMI-A-1,HDMI-A-2 bus-ID: 0000:01:00.0 chip-ID: 10de:2584 class-ID: 0300 Display: x11 server: X.Org v: 21.1.11 with: Xwayland v: 23.2.6 driver: X: loaded: modesetting,nouveau,nvidia unloaded: fbdev,vesa gpu: nvidia,nvidia-nvswitch display-ID: :0 screens: 1 Screen-1: 0 s-res: 2560x1440 s-dpi: 96 s-size: 677x381mm (26.65x15.00") s-diag: 777mm (30.58") Monitor-1: DP-1 mapped: DP-0 note: disabled pos: primary model: HP OMEN 32q serial: CNC4140L69 res: 2560x1440 hz: 60 dpi: 93 size: 697x393mm (27.44x15.47") diag: 800mm (31.5") modes: max: 2560x1440 min: 640x480 Monitor-2: Unknown-1 mapped: None-1-1 note: disabled size-res: N/A modes: 2560x1440 API: EGL v: 1.5 hw: drv: nvidia platforms: device: 0 drv: nvidia device: 2 drv: swrast gbm: drv: kms_swrast surfaceless: drv: nvidia x11: drv: nvidia inactive: wayland,device-1 API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: nvidia mesa v: 535.183.01 glx-v: 1.4 direct-render: yes renderer: NVIDIA GeForce RTX 3050/PCIe/SSE2

[Harry-W-Haines-III]

More info here about this issue. https://www.reddit.com/r/pop_os/comments/1bvguqd/solvedfixfixed_extra_unknown_display_after_kernel/

[Harry-W-Haines-III]

Work around mentioned here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2060268

[MiZoG99]

The strange thing is that Ubuntu 24.04 (I can switch back n forth between clonezilla OS images) with the same nvidia driver (535.x) is not affected by this. That actually made me to open this issue. My testing machine has seen dozens of installations and never experienced this bug. I will look into the workarounds soon when I get back to that machine.

[anaximeno]

There were some changes on muffin regarding the monitor manager, I wonder if they are related by any means https://github.com/linuxmint/muffin/commits/master/

[Harry-W-Haines-III]

I ran this suggested fix on a testing box = same hardware as this one. It seemed to fix the issue. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2060268/comments/32

[MiZoG99]

I do confirm that adding initcall_blacklist=simpledrm_platform_driver_ini as a boot parameter makes ghost monitor go away.

Still there hasn't been any such issue with nvidia-driver on any other distro and most importantly on Ubuntu 24.04 with the same version of the driver.

[Harry-W-Haines-III]

MiZoG99 Please read carefully that bug report. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2060268

[Harry-W-Haines-III]

Just found this same issue in POP!_OS, ISO number 41 (the current one for download).

[Harry-W-Haines-III]

It is odd that it doesn't show up in Ubuntu. Perhaps they patched the issue? Here is even more information. https://github.com/pop-os/pop/issues/3257

[Harry-W-Haines-III]

After installing and updating POP!_OS to the 6.9.3 kernel the "Ghost" monitor issue went away. FYI I also run the Nvidia driver v: 550.90.07 in the LM 22 Beta as well as LM 21.3. It is in the Ubuntu 22.04 repository. Can we now safely assume this is an 'upstream' issue?

[Harry-W-Haines-III]

Here with LM 22 Cinnamon fully updated using the xanmod 6.9.7 kernel.