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kerneldeimos

Member

Registered: 2024-07-11

Posts: 7

Asus Q508U - HDMI over USB-C not working

Setup:
- Kernel 6.9.8-arch1-1
- Sway/Wayland (also tried i3/X11)
- No login manager installed

Symptoms:
- Monitor connected to HDMI port on USB-C hub does not appear to be detected; "No Signal" message on display.
- Also tried a USB-C to HDMI cable; that didn't work either.
- `wayland-info` doesn't show the display.
- Built-in HDMI port works fine.
- Display connected to built-in HDMI turns on at boot time.

Notes:
- I `sudo pacman -Syu`'d, then remembered I should've `yay`'d and so I `yay`'d.
- Asus support told me the USB-C port supports DP Alt Mode.

Last edited by kerneldeimos (2024-07-11 05:06:06)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,076

Re: Asus Q508U - HDMI over USB-C not working

Is the usb-c port attached to the/a nvidia card? Xorg log from the i3 run?

lspci -knn
sudo journalctl -b | curl -F 'file=@-' 0x0.st

for general more information while the issue occurs

kerneldeimos

Member

Registered: 2024-07-11

Posts: 7

Re: Asus Q508U - HDMI over USB-C not working

`lspci -knn` output: http://0x0.st/XMtE.txt
`sudo journalctl -b` output: http://0x0.st/XMt6.txt

This is with the hub plugged in. The hub is called "VIA Labs" and it appears as two devices (if I'm interpreting that correctly).

I'm guessing this part is where I find out "no the usb-c is not attached to the nvidia card", is that accurate?

04:00.3 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne USB 3.1 [1022:1639]
	Subsystem: ASUSTeK Computer Inc. Device [1043:201f]
	Kernel driver in use: xhci_hcd
	Kernel modules: xhci_pci
04:00.4 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne USB 3.1 [1022:1639]
	Subsystem: ASUSTeK Computer Inc. Device [1043:201f]
	Kernel driver in use: xhci_hcd
	Kernel modules: xhci_pci

kerneldeimos

Member

Registered: 2024-07-11

Posts: 7

Re: Asus Q508U - HDMI over USB-C not working

Here's the xorg log (I missed that last time): http://0x0.st/XLYC.txt

It too only seems to see eDP-1 and HDMI-1.

Another interesting thing crosses my mind. There's AMD Radeon R7 graphics as well as Nvidia GeForce MX450. Are they able to work together somehow? This message form the xorg logs seems to convey that this isn't working:

[    19.316] (WW) VGA arbiter: cannot open kernel arbiter, no multi-card support