Comment 36 for bug 63418

I can confirm that this behaviour seems to be caused by ipw394 in conjunction with the kill switch:

I have a non-modified Dell Latitude D820 and with no cables attached (even power) and no media inserted the systems freezes during booting up as long as WiFi is disabled (kill switch set to ON). When I enable WiFi (kill switch OFF) the system boots again. I tested this behaviour several times now.

The freeze happens during starting of "LVM" or running fsck with the message "BUG: soft lockup detected on CPU#0!". Sometimes I also had the "Superblock last write time is in future. FIXED" message on my screen just before the freeze.

I am willing to deliever detailed information if needed.