Re: Problem with 2.6.17-mm2

[Ingo Molnar <mingo@elte.hu>]

* Thomas Gleixner <tglx@linutronix.de> wrote:

> On Sun, 2006-06-25 at 10:32 -0700, Andrew Morton wrote:
> > > So in fact this just silently acks spurious interrupts which have an
> > > hw_irq_controller assigned. If there is no action, then nothing has
> > > called setup_irq/request_irq for this interrupt line and therefor it is
> > > an spurious interrupt which should not happen.
> > > 
> > > 
> > > genirq makes these visible and informs noisily about those events. 
> > > 
> > 
> > hm, OK.  I guess we can let it ride for now.  Later we can decide whether
> > we need to shut that warning up.  I suspect we should, if the machine's
> > working OK.
> 
> We can make it once per IRQ.

yeah. A bit more sophisticated method would be to use a new sticky 
IRQ_SPURIOUS bit and only print a warning if it goes from 0 to 1. 
Whenever a real handler is installed the bit gets cleared. This will 
make behavior a bit more deterministic than 'once per bootup', and it 
will still not spam the box with printks. (Or never let that bit go from 
1 to 0 - this effectively implements the once-per-bootup warning.)

> In fact I think the original behaviour is a BUG. You have no chance to 
> notice that your box gets flooded by such interrupts. With my 
> willingly asserted spurious interrupts the box simply stalls in a 
> flood of interrupts without any notice.

hm, doesnt note_interrupt()/irqpoll detect and handle this to a certain 
degree?

	Ingo
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