On Tue, Dec 06, 2011 at 11:37:35AM +0000, Dave Martin wrote:

1) All OF code and drivers should be migrating to use 0 instead of NO_IRQ
   for the no-interrupt case.  Code which receives irq numbers directly
   from the OF framework and refers to NO_IRQ, or expects 0 to be a valid
   needs to be fixed.

2) Where we hit a problem, board code needs to be adapted to remap HW IRQs
   0-15 to different software values.  (This could be done using irq
   domains, or not)

No AMBA driver I'm aware of ever uses an IRQ number 0 or is passed such
an IRQ number.