Found the bug.  The following patch fixes the hot plug
driver so that it has a fallback when there are no unused
IRQs on a system.  At some point intialization got re-
ordered and this was broken.

I found another bug that was preventing the existing scheme from
working.  It looks like the function "pcibios_set_irq_routing" is
returning 1 for success, but the hot plug driver was interpreting it as
failure.