8572E - machine check pin (MCP0)

[Morrison, Tom]

Running 2.6.23.25 kernel...

I have an external watchdog timer that is going off - and pulsing into
the MCP0 of the 8572E. I get the printk indicating that the MCP0 went
off - the problem is - how do I clear the condition that caused this
because my hardware engineer swears that the pulse is ONLY 250ms - and
after resetting several status registers (mcpsumr & rst
(because my hardware engineer swears that the pulse is ONLY 250ms long
(and I have a delay after my printk of 250ms)) - so I am pretty sure

I am resetting the conditions mcpsumr (also, extra: the rstsr),
but after writing mcpsumr - and reading back - it still has 
the mcp0 bit set?

Where else do I need to reset the status - I think I am doing it
right...
but it isn't clearing the exception - and it 'dies' the next time
through
this (why is another problem - but first, I'd like to know why the
condition
is NOT being cleared...at all)...

A couple of possibilities is that because the external MCP0 condition
is actually a pulse - another machine check could be clocked in on the
'falling' edge - but this pulse is long gone before I even come close
to attempting clearing the mcp0 exception in mcpsumr?

FWIW, I also have the same signal pulsing to my UDE - and at least after
resetting the UDE condition, it 'looks' reset - before immediately
getting
another UDE interrupt (potentially for the falling edge)...

I am very confused here...

Thanks for any advice...

Tom