Kai-Heng, It has been filed:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1674390 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1672439 Title: No C-State Deeper than C3 utilized by Kaby Lake 7820HQ in Precision 5520 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1672439/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs