Comment by sgtnoodle

Did you muck with the kernel boot option to enable frequency and voltage adjustments? If so, the Arch wiki advice to set the bitmask to 0xffffffff will cause you problems. At some point they added an "async" driver mode that is incredibly glitchy, and it is enabled by one of those bits.

That caused me grief for many months until I figured it out. I updated Arch wiki about a month ago, and provided a command to compute a bit mask that avoids setting unnecessary feature bits.