External monitors not working

General system Newbie
1

Hi all,

i’ve recently done a fresh install of endeavour, switching from manjaro. Had some issues at the beginning concerning boot time, but that was fixed by adding the kernel parameter it=off and installing NVIDIA drivers.

Up until now, my external monitors are not working, i have connected them to my thunderbolt 3 dock via displayport, though plugging them in directly with HDMI also doesnt do anything. They are not showing up in the settings for display configuation.

I am on a lenovo p1 g4 with nvidia dedicated graphics, KDE Plasma, already installed bolt (and optimus manager)

I’ve also read on the forums already of issues with Plasma and externeal monitors. I am familliar with a bit buggieness of plasma, as i was also using it with manjaro. There my configuration was sometimes “forgotten” and the monitors were deactivated in the settings, i was able to activate them by going into the display settings, sellection the monitor and simply disabling the checkbox disabled thoug this time, the monitors arent even recognized by my system…

Thanks in advance for any help and tricks! :slight_smile:

My KDE version is 5.27

Edit: this is a windows dual boot machine, everything works fine with windows.

Edit 2:

Graphics:
  Device-1: Intel TigerLake-H GT1 [UHD Graphics] driver: i915 v: kernel
  Device-2: NVIDIA GA104M [GeForce RTX 3070 Mobile / Max-Q] driver: nvidia
    v: 525.89.02
  Device-3: Luxvisions Innotech Integrated RGB Camera type: USB
    driver: uvcvideo
  Display: x11 server: X.Org v: 21.1.7 with: Xwayland v: 22.1.8 driver: X:
    loaded: modesetting,nvidia dri: iris gpu: i915 resolution: 3840x2400~60Hz
  API: OpenGL v: 4.6 Mesa 22.3.4 renderer: Mesa Intel UHD Graphics (TGL GT1)

$ inxi -Ga
Graphics:
  Device-1: Intel TigerLake-H GT1 [UHD Graphics] vendor: Lenovo driver: i915
    v: kernel arch: Gen-12.1 process: Intel 10nm built: 2020-21 ports:
    active: eDP-1 empty: DP-1, DP-2, DP-3, DP-4, HDMI-A-1 bus-ID: 00:02.0
    chip-ID: 8086:9a60 class-ID: 0300
  Device-2: NVIDIA GA104M [GeForce RTX 3070 Mobile / Max-Q] vendor: Lenovo
    driver: nvidia v: 525.89.02 alternate: nouveau,nvidia_drm non-free: 525.xx+
    status: current (as of 2023-02) arch: Ampere code: GAxxx
    process: TSMC n7 (7nm) built: 2020-22 pcie: gen: 4 speed: 16 GT/s
    lanes: 16 ports: active: none empty: DP-5,DP-6,HDMI-A-2 bus-ID: 01:00.0
    chip-ID: 10de:249d class-ID: 0300
  Device-3: Luxvisions Innotech Integrated RGB Camera type: USB
    driver: uvcvideo bus-ID: 3-8:2 chip-ID: 30c9:0032 class-ID: 0e02
    serial: 01.00.00
  Display: x11 server: X.Org v: 21.1.7 with: Xwayland v: 22.1.8
    compositor: kwin_x11 driver: X: loaded: modesetting,nvidia dri: iris
    gpu: i915 display-ID: :0 screens: 1
  Screen-1: 0 s-res: 3840x2400 s-dpi: 96 s-size: 1016x635mm (40.00x25.00")
    s-diag: 1198mm (47.17")
  Monitor-1: eDP-1 model: LG Display 0x06aa built: 2020 res: 3840x2400
    hz: 60 dpi: 284 gamma: 1.2 size: 344x215mm (13.54x8.46") diag: 406mm (16")
    ratio: 16:10 modes: 3840x2400
  API: OpenGL v: 4.6 Mesa 22.3.4 renderer: Mesa Intel UHD Graphics (TGL GT1)
    direct-render: Yes
2

are the monitors recognized by xrandr?
xrandr --listmonitors
if they are you might need configure them with
https://wiki.archlinux.org/title/multihead

3

nope, the arent, neither with the dock, nor with hdmi directly…

4

allright, solved it:
I put optimus manager in hybrid mode for default, rebooted and now the monitors can be configured. Interestingly this didnt worked, when i manually put it in native nvidia mode and logged out.

Though i am only able to use the screens in 30Hz, these are 2x 4k 27" monitors which are capable of doing 60Hz. With manjaro I was able to use one in 60Hz and the other one in 30Hz, though this seemingly doesnt work now.

Edit:
well screw this, one monitor shows a screen, cannot move the mouse to there, configuration in settings app doesnt switch properly between screens now (settings options dont change anymore between integradet display and connected ones). Glitching errors occour in the settings app, this is a joke…

5

On many laptops with a dGPU, the vendors have the (external) video outputs connected to the gPU directly, so you have to have both GPU cards active to have all monitors accessible/working.
It seems this happens in case as well.

AFAIK, different frequency cannot work on monitors of the same GPU. I am not sure if this can happen when the monitors are connected to different GPUs, but you can experiment on this :person_shrugging: .

6

I also figured, that the hdmi port is directly connected to the gpu, though i am connectiong the monitors via the usb c connection from my dock…

using two different frequencies was the only option for using both monitors with manjaro, now i am only able to use one monitor and even that one continuosly goes off an on again…

7

with both connected, one shows up

0: +*DP-1-2.3 3840/620x2160/340+0+240  DP-1-2.3
1: +eDP-1 3840/344x2400/215+3840+0  eDP-1
8

I have never seen such an output name. Could be some issue with Xorg auto discovery?
I have no idea.

I would check the logs .
I would also check udev rules and tmpfiles.d. contents.

9

That depends on the model. ASUS ROG models - the dgpu is connected directly to the usbc display port, not the hdmi output. My Legion - I use the mux switch and turn off switchable grpahics right int he firmware and run everythhing through the dgpu.

10

hmm, well, this is the output, whe they are connected via DP to the dock and the dock connects to my laptop via usbc…

how can I provde the logs for you? :slight_smile: