Comment 380 for bug 1690085

I am using an AMD Ryzen 5 2400G on an Asus ROG Strix B350-F (firmware version 3805 and 3803 before that) and was also experiencing freezes, e.g. after about one hour into `rsync -a /home ...`, with Gentoo Linux (Linux 4.15.10), Arch Linux 2018.03.1, Fedora 27, Fedora 28 nightly, Fedora 28 beta. Setting rcu_nocbs=0-7, processor.max_cstate=5 or intel_idle.max_cstate=5 did not seem to have an effect -- the freezes still occurred. The hardware itself (mainboard, CPU, RAM) was cross-checked by the supplier, who found no fault in it. Since I disabled CPU C-states in the mainboard firmware about a day ago, I am no longer able to reproduce the freeze.