Running radeontop on discrete GPU prevents amdgpu crash and system hang. Any ideas why?

[dvoloshyn]

Hi,

Thank you for creating this nice piece of software.
Your knowledge of amdgpu and radeontop is much needed.
Briefly. Asus ROG Strix G15 Advantage Edition G513QY laptop. iGPU has eDP, HDMI. dGPU has DP over USB-C. If I have USB-C monitor connected amdgpu crashes and system hangs shortly after boot.
But if I keep running sudo radeontop -b 3 (3 is the dGPU PCI bus) the system works fine.
Relevant amdgpu issues with full information: 1861, 1748.
Any ideas why it happens? Or, maybe, direction to follow, things to try out?
Would appreciate your help.

[clbr]

Presumably radeontop keeps the dgpu from going to sleep. If it's a bug in the sleep path, some interaction with the amdgpu and usb side is going wrong. Such screens are probably pretty rare, and a combo with a dual-gpu laptop too, it's likely nobody has tested that combo.

As for what you can do, beyond filing the bug reports, not much if you can't code. There may be a /sys switch that prevents the dgpu from sleeping, which may be a bit more efficient than running radeontop dump mode in the background.

[dvoloshyn]

Yes, looks like the GPU is switched off or put to sleep and is not properly awoken.
Will continue investigating with DRM devs.

Thank you, clbr