8572E - machine check pin (MCP0)

[Trent Piepho]

On Mon, 24 Nov 2008, Morrison, Tom wrote:
> 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)...

SRESET# also sets MCP0 and MCP1, maybe that is on?

I'd also check the EMCP bit in SPRN_HID0 (on core 0 for MCP0).