amdgpu debug

[James Dutton]

Hi,

I wish to debug the amdgpu driver with regards to plugging and
unplugging display port cables and screens.
So, I would like to see the plug/unplug events, the negotiation of
link parameters: swing / pre-emphasis.
I have a display that is not sensed on a particular laptop running
Linux with the amdgpu driver, whereas the same display and cable works
fine on a different laptop with an intel GPU.
I think there is a bug in the amdgpu driver, but I need some extra
debug output, but just for the plug/unplug/link negotiation.
Please can someone point me to which debug variable to tweak to get
the debug messages I need, without being flooded with too many
messages.

Kind Regards

James