Colin, finally I tried booting with noapic. The problem appears to go away (as with acpi=noirq) and it doesn't freeze the machine with excessive USB activity (like acpi=noirq).
I'll try suspending and resuming next and see how that goes. I did another interrupt diff, see attached. ** Attachment added: "irq_delta_noapic.log" http://launchpadlibrarian.net/14501691/irq_delta_noapic.log -- Powertop reports huge number of wakeups and drains battery https://bugs.launchpad.net/bugs/145377 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs