HDMI connection is not stable on eGPU

NVIDIA Open GPU Kernel Modules Version

570.124.04

Please confirm this issue does not happen with the proprietary driver (of the same version). This issue tracker is only for bugs specific to the open kernel driver.

• I confirm that this does not happen with the proprietary driver package.

Operating System and Version

Manjaro Linux

Kernel Release

6.12.17-1-MANJARO

Please confirm you are running a stable release kernel (e.g. not a -rc). We do not accept bug reports for unreleased kernels.

• I am running on a stable kernel release.

Hardware: GPU

GPU 0: NVIDIA GeForce RTX 3060

Describe the bug

NVIDIA driver has issues with detecting HDMI connection on eGPU on Thunderbolt 3.
Sometimes it works, sometimes it doesn't.

The issue happens sometimes with modeset=1, and always with modeset=0. To make it work I have to make sure eGPU is connected during boot and modeset=1 is set, but if eGPU is not connected during boot or reconnects - it's not possible to enable HDMI.

If I unload nvidia driver and load nouveau kernel module - it detects HDMI without any issues immediately on the same machine without reboot, but that driver has many other issues.

To Reproduce

easy way is to set modeset=0 , harder way to find a reason why it sometimes detects and sometimes not with modeset=1, but it's definitely not stable

Bug Incidence

Always

nvidia-bug-report.log.gz

nvidia-bug-report.log.gz

More Info

No response

Start by reviewing the attached nvidia-bug-report.log.gz and reproducing the HDMI detection behavior on the listed Manjaro kernel with an RTX 3060 eGPU. Compare modeset=0 and modeset=1, including booting without the eGPU and reconnecting it; done means HDMI is detected reliably without requiring the eGPU to be connected during boot.