Re: [PATCH v3] irqchip: Add support for ARMv7-M's NVIC

Arnd Bergmann
2013-04-18T09:01:37Z

On Thursday 18 April 2013, Uwe Kleine-König wrote:
> > > + * Each bank handles 32 irqs. Only the 16th (= last) bank handles only
> > > + * 16 irqs.
> > > + */
> > > +#define NVIC_MAX_IRQ ((NVIC_MAX_BANKS - 1) * 32 + 16)
> >
> > Is this actually inherent to the hardware design, or is the number of irqs
> > actually customizable? Also, why do you care about the maximum? You only
> > use it to check against the device tree provided value, but I suppose
> > you could just as well trust that property to be correct.
> I don't provide a value for the number of irqs in the device tree. There
> is only the value INTLINESNUM in the V7M_SCS_ICTR register that is used
> to determine the number of interrupt banks.

Ah, right. But do you have any reason to believe it could be wrong?

Arnd