Found a really fun one. Plug in or unplug my headphone, and my computer locks up. This is with hda-intel with msi-enable. Apparently the headphone plugging/unplugging generates an interrupt. I am using msi-enable. When the thing sleeps and comes back from sleep, sometimes the kernel, the BIOS, ACPI, and the snd-hda-intel driver aren't in agreement as to what IRQ the thing is on. Sometimes I end up with this: 16: 1321610 IO-APIC-fasteoi uhci_hcd:usb5, i915@pci:0000:00:02.0, HDA Intel 218: 2 none-edge 219: 3063329 none-edge I've got RT kernel, and the IRQ-219 is set to highest priority. 1673 FF 85 - 125 0.2 S< IRQ-219 Now, if I am careless enough to generate an interrupt by plugging in the headphone, the system will lock-up, hard-core. I can avoid the problem by whacking the snd-hda-intel driver with a ball-peen hammer until it decides to go back onto the correct IRQ again: sudo modprobe -r snd-hda-intel sudo modprobe snd-hda-intel Yay, 16: 1337804 IO-APIC-fasteoi uhci_hcd:usb5, i915@pci:0000:00:02.0 219: 3063459 PCI-MSI-edge HDA Intel And no problem. :-) -ken