[O/S] New Debian 12 Install Restarting/Shutting down causes system to hang - need assistance troubleshooting

[pgharibi]

Hello,

First post as a new member, so go easy on me.

I just successfully installed Debian 12 with KDE two days ago.

Hardware:
Lenovo Thinkpad T14 Gen2A Ryzen 7
32GB RAM

Machine is about 3 years old.

I'm moving from Mint 22, which worked perfectly for me. I've spent the last two days configuring and installing the software that I want. During restart/shutdown I am finding the OS is hanging and one of two pieces of the final line text on the hanging screen are displaying. It hangs about 50% of the time, other 50%, it shuts down as expected. 50% of hangs display one text, the other half displays the other.

"[drm:dc_dmub_srv_wait_idle [amdgpu]] *ERROR *Error waiting for DMUB idle: status=3"

or

"The system will shutdown now!"

On the amdgpu line, it hangs indefinitely as far as I can see.
On the second line, it hangs for about 1.5 minutes, then reboots.

I thought it might be an issue with an outdated kernel, so I backported the kernel to the latest one available "6.10.6+bpo-amd64". This did not resolve.
I also tried updating the AMD firmware but it shows that it is already running the latest version (although the date is February 2023, which seems old to me).

I posted the same issue on reddit and received lots of good suggestions that I tried, but nothing that resolved my hang problems so I thought I would check with the experts here.



Any help you guys can provide will be very much appreciated.

[nikobit]

I'm not an expert per se. But had almost the same problem with previous grade of Debian. What helped me was re-installing the whole system from the scratch with as minimum graphic environment as possible. Thus by exception method you might exclude what breaks your installation. Like - first minimum system without any GUI - like command line only. Then - add less demanding Desktop Environment, like 'xfce' or any other. Finally you might get KDE working by installing it from the shell. But don't rely on my advice much!