[PATCH 2/2] uio: add an of_genirq driver

Alan Cox alan at lxorguk.ukuu.org.uk
Mon Jun 15 18:44:49 EST 2009


> I did it that way because I saw IRQ 0 in /proc/interrupts on every PC...
> 
> > 
> > It is the job of the platform to map a physical IRQ 0 to some other
> > representation if it exists outside of arch specific code.
> 
> Funny.
> 
> > This was
> > decided some years ago and a large part of the kernel simply doesn't
> > support any notion of a real IRQ 0.
> 
> Can you tell me the reason for that decision or point me to some ml archive?

The natural C way to write "No xxx" is if (!xxx) hence

	if (!dev->irq) {
		polling_start();
		return 0;
	}

The PC "IRQ 0" is the timer - which only appears in the arch code.

Alan


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