7.2-STABLE: Inserting USB device causes Fatal Trap 12

[Norbert Papke]

On May 10, 2009, Norbert Papke wrote:
> Inserting a USB thumb drive into a running sytem result in a "Fatal trap
> 12: page fault while in kernel mode".

After repeating the crash a few times with INVARIANTS enabled, it becomes 
apparent that EHCI transfer queue is getting corrupted.

With High Precision Event Timers disabled in the BIOS, the problem goes away.  
This is an acceptable work-around for me.  I am inclined to believe (but 
unable to prove) that the crash is due to a BIOS bug.

Cheers,

-- Norbert Papke.