It looks like the USB driver is having trouble with the keyboard,
possibly an indication that the USB interrupt is not working.
Try plugging the USB keyboard into a different USB port.
--
If that doesn't help, then emergency interrupt polling can be enabled
and you can try bumping the frequency up as a workaround.
sysctl kern.emergency_intr_enable=1
sysctl kern.emergency_intr_freq=50
-Matt
