quiet is an alias for loglevel=4, debug is for loglevel=10. Try loglevel=3 and lower until you don't see those messages anymore. Try not to jump straight to 1, because you still want to see the critical messages like your cpu exploded
Could you post the exact message? If I can find it in the source, I'll be able to tune it's loglevel up so it won't show up on "quiet" anymore (after the next kernel update)