My Lenovo T61 occasionally goes crazy with interrupts under kernels >= 2.6.28. powertop shows the situation clearly: Top causes for wakeups: 99.4% (64644.0) <interrupt> : ahci, uhci_hcd:usb5, yenta, i915 at pci:0000:00:02.0 How does one tell which device is causing all these interrupts?