I’ve been chasing a weird problem since I got this laptop last year and using their TB4 dock with this laptop with Arch, it simply will not launch ANY DM (SDDM, GDM, LXDM) on the nvidia drivers with more than the built-in display and seems like 1 external display on the dock, not 3, not 2. Very weird problem, but quite annoying as I have to disconnect my dock to boot into a DM and log in, and plug it back in after and re-layout the desktop.
This is a Thinkpad T15g Gen2 with a 3080GTX chip, and forcing the Nvidia GPU in the bios, so the intel is never used nor any Optimus mess any more than needed. This works fine in the desktop, where I drive 3x external 4k displays in 30hz, but again only once the desktop is up fully and logged into. Currently 6.1.12 kernel, nvidia 525.89.02, and happens regardless of the DE, never gets that far.
Digging in deeper at the boot, linux will start normally, go to load the DM, and I have to jump into a local tty to investigate. Observing journalctl and X logs, the nvidia drivers start as normal, see all 4 displays, but then just oddly fails there with only thing odd was there failing to acquire modesetting permissions:
[ 2669.962] (II) NVIDIA(0): Detected PCI Express Link width: 16X
[ 2670.041] (EE) NVIDIA(GPU-0): Failed to acquire modesetting permission.
[ 2670.044] (EE) NVIDIA(0): Failing initialization of X screen
[ 2670.045] (II) UnloadModule: "nvidia"
[ 2670.045] (II) UnloadSubModule: "glxserver_nvidia"
[ 2670.045] (II) Unloading glxserver_nvidia
[ 2670.045] (II) UnloadSubModule: "wfb"
[ 2670.045] (EE) Screen(s) found, but none have a usable configuration.
Then, once I disconnect all but one display, and restart sddm this time adding all the interfaces:
[ 2669.962] (II) NVIDIA(0): Detected PCI Express Link width: 16X
[ 2670.040] (--) NVIDIA(GPU-0): SAMSUNG (DFP-6.1.6): connected
[ 2670.040] (--) NVIDIA(GPU-0): SAMSUNG (DFP-6.1.6): Internal DisplayPort
[ 2670.040] (--) NVIDIA(GPU-0): SAMSUNG (DFP-6.1.6): GUID: 10DE9070-0005-F4D5-DB4E-32FA000000FB
[ 2670.040] (--) NVIDIA(GPU-0): SAMSUNG (DFP-6.1.6): 2670.0 MHz maximum pixel clock
[ 2670.040] (--) NVIDIA(GPU-0):
[ 2670.044] (--) NVIDIA(GPU-0): DFP-0: disconnected
[ 2670.044] (--) NVIDIA(GPU-0): DFP-0: Internal DisplayPort
[ 2670.044] (--) NVIDIA(GPU-0): DFP-0: 2670.0 MHz maximum pixel clock
[ 2670.044] (--) NVIDIA(GPU-0):
[ 2670.044] (--) NVIDIA(GPU-0): DFP-1: disconnected
[ 2670.044] (--) NVIDIA(GPU-0): DFP-1: Internal TMDS
[ 2670.044] (--) NVIDIA(GPU-0): DFP-1: 165.0 MHz maximum pixel clock
[ 2670.044] (--) NVIDIA(GPU-0):
[ 2670.044] (--) NVIDIA(GPU-0): DFP-2: disconnected
[ 2670.044] (--) NVIDIA(GPU-0): DFP-2: Internal DisplayPort
[ 2670.044] (--) NVIDIA(GPU-0): DFP-2: 2670.0 MHz maximum pixel clock
[ 2670.044] (--) NVIDIA(GPU-0):
[ 2670.044] (--) NVIDIA(GPU-0): DFP-3: disconnected
[ 2670.044] (--) NVIDIA(GPU-0): DFP-3: Internal TMDS
[ 2670.044] (--) NVIDIA(GPU-0): DFP-3: 165.0 MHz maximum pixel clock
[ 2670.044] (--) NVIDIA(GPU-0):
[ 2670.045] (--) NVIDIA(GPU-0): DFP-4: disconnected
[ 2670.045] (--) NVIDIA(GPU-0): DFP-4: Internal TMDS
[ 2670.045] (--) NVIDIA(GPU-0): DFP-4: 165.0 MHz maximum pixel clock
[ 2670.045] (--) NVIDIA(GPU-0):
[ 2670.046] (--) NVIDIA(GPU-0): CSO (DFP-5): connected
[ 2670.046] (--) NVIDIA(GPU-0): CSO (DFP-5): Internal DisplayPort
[ 2670.046] (--) NVIDIA(GPU-0): CSO (DFP-5): 2670.0 MHz maximum pixel clock
[ 2670.046] (--) NVIDIA(GPU-0):
[ 2670.046] (--) NVIDIA(GPU-0): DFP-6: disconnected
[ 2670.046] (--) NVIDIA(GPU-0): DFP-6: Internal DisplayPort
[ 2670.046] (--) NVIDIA(GPU-0): DFP-6: 2670.0 MHz maximum pixel clock
[ 2670.046] (--) NVIDIA(GPU-0):
[ 2670.052] (--) NVIDIA(GPU-0): DFP-7: disconnected
[ 2670.052] (--) NVIDIA(GPU-0): DFP-7: Internal TMDS
[ 2670.052] (--) NVIDIA(GPU-0): DFP-7: 165.0 MHz maximum pixel clock
[ 2670.052] (--) NVIDIA(GPU-0):
[ 2670.183] (==) NVIDIA(0):
[ 2670.183] (==) NVIDIA(0): No modes were requested; the default mode "nvidia-auto-select"
[ 2670.183] (==) NVIDIA(0): will be used as the requested mode.
[ 2670.183] (==) NVIDIA(0):
[ 2670.186] (II) NVIDIA(0): Validated MetaModes:
[ 2670.186] (II) NVIDIA(0): "DFP-5:nvidia-auto-select,DFP-6.1.6:nvidia-auto-select"
[ 2670.186] (II) NVIDIA(0): Virtual screen size determined to be 7680 x 2160
[ 2670.264] (--) NVIDIA(0): DPI set to (286, 288); computed from "UseEdidDpi" X config
[ 2670.264] (--) NVIDIA(0): option
[ 2670.264] (II) UnloadModule: "modesetting"
[ 2670.264] (II) Unloading modesetting
[ 2670.264] (II) UnloadModule: "vesa"
[ 2670.264] (II) Unloading vesa
I don’t understand why it should matter to the system really, but it gladly lets me go reconnect the other two up and set them up again.
Any idea why this would be? I tried adding nvidia-drm and other bits in 10-nvidia-drm-outputclass.conf as recommended, but same with or without. I’ve not run into this as my last desktop I ran arch with nvidia (1070gtx) on as well with 3 displays in the exact same config minus the dock, but several years ago.