New user had the same problem.
Since the dmesg output hinted that the nuveau driver might be the problem I decided to reinstall the current proprietary NVIDIA drivers and the problem went away, though my previous problem (why I uninstalled them a few months ago) came back: when the laptop tries to go to sleep while I have mounted a remote directory via sshfs it just freezes up and I have to kill him with REISUB.