Re: [PATCH] irq: handle irq0 special only on x86

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

Hello,

On Wed, Dec 09, 2009 at 05:28:09PM +0800, Américo Wang wrote:
> 2009/12/9 Uwe Kleine-König <u.kleine-koenig@pengutronix.de>:
> > I just noticed this when digging in the irq handling.  At least for arm
> > this doesn't make sense.  Not sure if x86 is the only arch this test
> > is valid for, but probably it is.
> 
> No, it is not.
> 
> Try grep -Inr 'irq0' arch/*/kernel.
Some hits are unrelated, some others are usage of an irq0.  AFAIK irq0
is reported on x86 for misrouted irqs[1].  I think on other archs it's just
an ordinary irq.  If you still think I missed something in the output of
your grep, please be a bit more specific.

Thanks
Uwe

[1] I don't really know x86, so this might be complete non-sense.

> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: Ingo Molnar <mingo@redhat.com>
> > Cc: H. Peter Anvin <hpa@zytor.com>
> > ---
> >  kernel/irq/spurious.c |    2 ++
> >  1 files changed, 2 insertions(+), 0 deletions(-)
> >
> > diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
> > index 22b0a6e..4996b66 100644
> > --- a/kernel/irq/spurious.c
> > +++ b/kernel/irq/spurious.c
> > @@ -199,8 +199,10 @@ try_misrouted_irq(unsigned int irq, struct irq_desc *desc,
> >        if (irqfixup < 2)
> >                return 0;
> >
> > +#if defined(CONFIG_ARCH_X86)
> >        if (!irq)
> >                return 1;
> > +#endif
> >
> >        /*
> >         * Since we don't get the descriptor lock, "action" can
> 

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