Re: Bug in "genirq: record trigger type"

From: Benjamin Herrenschmidt
Date: Tue Oct 21 2008 - 04:31:26 EST


On Tue, 2008-10-21 at 01:01 -0700, David Brownell wrote:
>
> I'm a bit more curious about another potential issue though ... as
> described in the patch comment:
>
> - Make set_irq_type() usage match request_irq() usage:
> * IRQ_TYPE_NONE should be a NOP; succeed, so irq_chip methods
> won't have to handle that case any more (many do it wrong).
>
> It might be a bit more accurate to say irq_chip.set_type() methods
> are *inconsistent* in handling IRQ_TYPE_NONE. Previously the
> set_irq_type() method would pass that down to irq_chip code.
>
> I had observed two behaviors, but I thought I observed a third one
> in some of the PowerPC code:
>
> (1) ignore it ... matching request_irq() usage
> (2) return an error ... nasty
> (3) assign some irq_chip-specific trigger mode
>
> That third behavior might cause a bit of trouble, but I think
> it was only used during platform init. Someone more attuned
> to PowerPC might want to check ...

Ok, I wrote a lot of the port of powerpc stuff to genirq so I supposed
I'm the person to do that sweep :-) I'll have a look tomorrow.

Thanks for the heads up,

Cheers,
Ben.


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