Fix for X13 Yoga Gen 3 pkg C-States
The cause of the problem is found. It’s the smartcard reader service, pcscd. At boot up, it pegs the reader to 100% use.
It only takes a restart of the socket with sudo systemctl restart pcscd.socket to resume the normal behaviour and allow the system to go to C10.
Lenovo is also now looking into possible issues with the firmware of the X13 Yoga Gen3.
This issue has drawn the attention of everyone involved, Fedora/RedHat, the pcscd creator and Lenovo. Amazing job.
Obviously if your X13 Yoga Gen3 has no smartcard reader, this is not going to be an issue.
I wonder if other Thinkpads (Alder Lake or later) with a smartcard reader may have the same problem.