I'm having this problem on two second hand hp business machines with ... I think discrete graphics but now that I'm writing this I never bothered to check. I'm running Ubuntu on them and they basically run Minecraft and flightgear a few times a day. Not every time, but eventually when either machine attempts to enter suspend mode it will instead crash and stay like this until a manual hard reset. I suspect this is related to certain software running when suspend is initiated but I'm not sure.
I'm not using Ubuntu much myself these days and I've never used a Radeon GPU, any advice or ideas would be appreciated. If anyone wants to dig in I can get hardware info and logs, I'm feeling lazy at the moment.
What GPU are we talking about?
Your kernel is defaulting to the radeon driver instead of amdgpu, depending on which generation your GPU belongs to, you can force the kernel to use amdgpu instead. It's considered unsupported but you're still going to be much better off running the much newer amdgpu, if your hardware is still capable of using it.