Just updated to 20180212, kernel 4.15.2-1. Error persists. I cannot remove the old kernels because they are no longer in the repo and I cannot revert. Did anything specific to reboot change? I also have to use these kernel command line options, which work with 4.14: nouveau.config=NvMSI=0 nouveau.nofbaccel=1 nouveau.runpm=0 reboot=warm,pci