On Mon, 2008-06-23 at 04:28 -0700, David Brownell wrote: > On Monday 23 June 2008, Benjamin Herrenschmidt wrote: > > NO_IRQ on x86 is 0 > > There is no such #define for it. > And since zero is used for timer IRQs, it's not invalid.
I'll refer you to past discussions with Linus here. 0 is invalid to drivers for all intend and purposes.