Re: [PATCH v2 3/3] sam460ex: Clean up irq mapping

[Peter Maydell]

On Thu, 31 Dec 2020 at 20:55, BALATON Zoltan <balaton@eik.bme.hu> wrote:
> The SoC is called 460EX (despite having a PPC 440 core not 460 one) but I
> think you've looked at the right data sheet and it's just a typo. I also
> don't know how the board is wired so I think in this case I prefer
> dropping this patch and keeping the current code just for simplicity but
> to avoid going through this again maybe we should add a comment saying why
> it's working. Can you please suggest a text for such comment pointing to
> the relevant part of pci_change_irq_level() you refer to above? I don't
> think I understand it enough to document it.

How about:

/*
 * All four IRQ[ABCD] pins from all slots are tied to a single board
 * IRQ, so our mapping function here maps everything to IRQ 0.
 * The code in pci_change_irq_level() tracks the number of times
 * the mapped IRQ is asserted and deasserted, so if multiple devices
 * assert an IRQ at the same time the behaviour is correct.
 */

?

thanks
-- PMM