Created attachment 126886 [details]
Screenshot

I might have spoke too soon with the memory manager patches, I'm seeing a stack
trace just as the machine is just about to switch off.

Also it takes about 30 seconds to switch off my laptop now, I think it's amdgpu
related, it seems to wait then fire up the card then switch off - it could also
be hard disk or even systemd related though.

I'm attaching the screen shot but it looks like an issue with
ttm_bo_force_list_clean

Sorry about the bad quality but I had to record a video in slowmo to capture
it, then screenshot that