Switching from Nvidia to Intel Integrated graphics broke use of external monitor

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I have an HP Omen laptop with Nvidia graphics. I switched it to “Intel Graphics” mode and it has lost the dual monitor ability. I normally use it as if it was in a docking station with external mouse, keyboard and monitor. The external mouse and keyboard still work fine

My motivation for doing this is to use the Integrated GPU with OpenVINO.

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I don’t have a solution, but changing the setting to Nvidia On demand got my external monitor working again, and I could still use cuda.

OpenVINO reports CPU, GPU.0 Intel , GPU.1 Nvidia, but I get an error trying to use the OpenVINO GPU.0, looks like the Ultralytics yolo library is still trying to use cuda here. Issue is not relevant here, unless I need to do something to make the Intel GPU become active before using OpenVINO.

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I don't even know what that means?

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Setting NVIDIA to "On Demand", essentially, modifies the contents of /lib/modprobe.d/. Same with if we set it to "Intel (Power Save)" (i.e. prime-select intel). The latter will effectively blacklist the NVIDIA GPU altogether (check the contents of /lib/modprobe.d to be sure).

I suspect that when you blacklist the NVIDIA driver, you are also - possibly - disabling display via USB-C.

If I plug my monitor into the HDMI port on my laptop, and use inxi -Gxx I'll see:

Graphics:
  Device-1: NVIDIA TU106M [GeForce RTX 2060 Max-Q] vendor: ASUSTeK
    driver: nvidia v: 550.163.01 arch: Turing pcie: speed: 2.5 GT/s lanes: 8
    ports: active: none empty: DP-1 bus-ID: 01:00.0 chip-ID: 10de:1f12
  Device-2: AMD Renoir [Radeon RX Vega 6 ] vendor: ASUSTeK driver: amdgpu
    v: kernel arch: GCN-5 pcie: speed: 16 GT/s lanes: 16 ports:
    active: HDMI-A-1,eDP-1 empty: none bus-ID: 05:00.0 chip-ID: 1002:1636
    temp: 46.0 C
...

See that bit where it says active: HDMI-A-1,eDP-1 for Device 2? That's my AMD iGPU handling the HDMI port.

If I connect the monitor via USB dock through to USB-C port then I still see ports: active: none empty: DP-1 on the NVIDIA card with inxi but the external display is listed as:

...
Monitor-1: DP-1-0 pos: primary,left res: 1920x1080 dpi: 93
    diag: 604mm (23.8")

Looking at this and the output of lspci I'm confident that, basically, the HDMI port on my laptop is backed by the AMDGPU, but the USB-C display seems to be backed by the NVIDIA card (of all things). That would probably explain why when you blacklist the NVIDIA driver, the external monitor stops working (if your setup is anything like mine).

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Thank you for some info about what is likely going on behind the scenes with these multi GPU laptops. It is a mess if you want to use multi-monitor or “docking station” setups. My pet peave is that when I’m using external 4K monitor on my 1440p Omen notebook with the lid closed (which is basically always) I can’t reboot it without opening the lid as it gets stuck in a logout-login loop until I open the lid. This machine runs 22.04 but can dual boot into 20.04, where the issue is, if anything, worse as sometimes opening the lid is not enough to break the log out/in loop and complete the shutdown or reboot and I need a hard power cycle.

It also happens on my old ASUS laptop which is dual boot 20.04 and 16.04. I suspect most people that get a laptop with dual graphics chips want to normally use the “best” one.

I want to switch to use OpenVINO or Cuda as I continue to improve my AI system that monitors our security cameras. It does work very well on a bottom of the line 11th gen i3 with integrated graphics laptop for 6 4K cameras. I’ll have to try the external monitor on this system just to see if it can reboot with the lid closed.

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Just for grins I played a bit with my Lenovo 11th gen i3 laptop that only has Intel integrated graphics running Mate-20.04. I’d never used it with an external monitor & mouse/keyboard before.

It let me restart with the lid closed and the external KVM active. Of course I had to open the lid to power on after shutting down.

I think the key was that I disabled the laptop screen in “Displays” after I noticed that things were opening on the invisible closed laptop screen, and re-did the “Apply” step. With the KVM disconnected it booted normally as a laptop, and returned to “docked” config when I plugged into the KVM again. Don’t know if this is a general solution or only works because there is only integrated graphics on this Lenovo, all my other laptops have Nvidia graphics chips as well as the Intel integrated GPU.

This is what I consider “proper” docking station behavior. I will try disabling the laptop screen on my 22.04 system and see if it fixes this annoyance of not being able to reboot with the lid closed when on KVM.

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