So from the descriptions above, it sounds like the Lenovo BIOS SMI handling is not supporting x2apic mode. Will post a kernel patch to blacklist x2apic enabling on this system, once I figure out what I need to use for the blacklist.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/776999 Title: [Lenovo W520] laptop freezes on ACPI-related actions To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/776999/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs