How to find source of a panic event?

[Giuseppe Sacco <giuseppe@eppesuigoccas.homedns.org>]

Hi all,
I am testing new kernels on a spare O2. Since I see some strange behaviour, I 
would like to ask you for a comment on this subject.

What happens is that when the kernel is loaded and then started, the led 
immediately start blinking red/green and the machine power off after 120 
seconds.

Looking at arch/mips/sgi-ip32/ip32-reset.c I found that when setting up the 
system, a new interrupt is requested, MACEISA_RTC_IRQ, and a notifier_block 
structure is setup in order to be used when a panic action is triggered. When 
this happens, the panic action uses the interrupt to wait two minutes and power 
off the machine.

So I wonder how to find the source calling this panic_action.

Thanks to all,
Giuseppe