Systemd service file only works if GPU is plugged in at startup

[WhyNotHugo]

Given that this only runs one and exits, the systemd service only turns of the GPU if it's plugged in during startup.

If I turn on my laptop, and plug in the GPU a minute later, then the service will have already exited, and has no effect.

I believe that is should actually linger in background, or somehow monitor new devices being plugged in to work properly.

[michelesr]

Why would you ever need to plug the card after turning the laptop?

[WhyNotHugo]

I'm using an eGPU, which stays on my desk, but go back and forth with my laptop.

[michelesr]

Oh yeah, eGPU. Didn't know you could do that in GNU/Linux too. I'd say that given that the PM logic on nvidia-xrun relies primarily on device add/remove, that daemon could clash with it quite easily if not implemented in the right way.

Meanwhile, isn't there a way to physically turn the card off (like a switch or simply unplugging maybe)? Because you can simply set ENABLE_PM=0 and turn off the card when it's not used.

[WhyNotHugo]

The case itself provides power to the laptop and the PCI-E data over the same cable, so turning it off means I'd start to run on battery (it's also a USB hub as well).

I'd actually like to turn off the video card because it's quite noisy when not being used too (as well as wasting power).

[michelesr]

I understand. Right now the only way is to restart the systemd service or run the command manually (as root user):

$ TURN_GPU_OFF_ONLY=1 /usr/bin/nvidia-xrun

Maybe you can hook this to a udev rule?