Re: irq consolidation

[Anton Blanchard]

> I believe Andrey's IRQ consolidation provides a single flat IRQ
> structure.  Unfortunately, this doesn't reflect the reality that we
> have on many ARM platforms - it remains the case that we need to
> decode IRQs on a multi-level basis.

Yes its still a flat structure. On ppc32/64 we offset the interrupts on
the main controller to provide a space for ISA interrupts to go. Not
great but it works for us.

One thing Paul suggested was to have a flag to mark an interrupt as a
cascade in the irq descriptor. If its set then we also provide a
get_irq() method (perhaps stashed away in the ->action field). That gives
us nested interrupt handling in generic code. (assuming you can
partition your irq numbers somehow)

Anton