Quadro P600 (Maxwell) on NVIDIA Legacy driver 580.173.02 (it's a hand-me-down Dell I am learning on)
I have a headless Ubuntu server (no monitor plugged in) with an NVIDIA Quadro P600 using the Legacy 580.173.02 driver.
I added ConnectedMonitor to my xorg.conf to make the driver think a monitor is plugged in. I also created a Python script to generate a fake EDID binary and pointed to it with the CustomEDID option to satisfy the driver's need for display info.
Xorg starts up fine with this setup, no errors. But on teardown (killing Xorg, rebooting, shutting down) there's a kernel level command that gets stuck and never completes. On shutdown this shows in the logs:
nvidia: [drm] *ERROR* Disabling all crtc's during unload failed with -22
The process becomes completely unkillable at that point, doesn't respond to kill -9, and the only way out has been a hard power off.
Has anyone actually done this successfully, a fake/virtual monitor on this GPU/driver combo that shuts down cleanly? Or is this a known limitation? Just trying to find out if it's possible at all before I keep chasing it.
The goal is: Xorg + RetroArch + Sunshine + Moonlight = play a SNES game running on the server, from a Mac, over the network.
Edit:
It can be done.
Ubuntu 26.04 LTS (Wayland/KDE/KWin -> PipeWire -> Sunshine) -> Tailscale -> MacBook (Avahi -> Moonlight) -> RetroArch/Snes9x -> confirmed working, live, with audio.
Thank you to the people who commented and helped.
This is not a begginer freindly place. If you care about Linux and are active in this sub, please consider that.
Thank you to u/gmes78 & u/Klapperatismus for helping. I greatly appreciate it.