Tried 5.9.1 mainline kernel and got the same issue. The only difference is Wayland recovered much faster (under 1 min). I didn't wait after recovery to see if system will lockup completely and rebooted with proprietary driver. Attaching dmesg output.
** Attachment added: "dmesg_5.9.1_mainline.log" https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/1901294/+attachment/5426606/+files/dmesg_5.9.1_mainline.log -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1901294 Title: nouveau timeout and system lockup To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/1901294/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs