Messages in this thread | | | Subject | Re: [PATCH] genirq: irq_chip->startup() usage in setup_irq and set_irq_chained handler | From | Benjamin Herrenschmidt <> | Date | Wed, 27 Aug 2008 10:06:59 +1000 |
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On Tue, 2008-08-26 at 11:14 +0100, Pawel MOLL wrote:
> Let me briefly explain my situation. I have a main interrupt controller > which provides startup() and unmask/mask() functions. The first one is > rather expensive (as the controller itself is... hmmm... > complicated ;-), the second - very cheap. And that is how I understand > the different "levels" of interrupt access - startup() should be called > once, somewhere during request_irq(), (un)masking may be used > frequently.
Oh, I don't disagree. It's probably a good idea. I'm just worried of the potential impact on existing code written around the current behaviour.
We have 23 calls to set_irq_chained_handler in arch/powerpc, and I need to audit them all. Luckily, we mostly don't have startup() callbacks.
(... some time later ...)
It looks good. Of course, we'll have to test at one point, but at this stage, I think powerpc is happy with the change.
Interestingly enough, I can see a case where we would have a problem -without- your change :-) Not with the current code, but in conjunction with another change that's planned for .28.
So Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cheers, Ben.
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