On Mon, 20 Nov 2006, Russell King wrote: > > On Mon, 20 Nov 2006 12:54:32 +0100 (MET) > > Stefan Roese <ml at stefan-roese.de> wrote: > > > Let's see, if I got this right. You mean that on such a platform, where 0 > > > is a > > > valid physical IRQ, we should assign another value as virtual IRQ number > > > (not > > > 0 and not -1 of course). And then the platform "pic" implementation > > > should > > > take care of the remapping of these virtual IRQ numbers to the physical > > > numbers. > > Since IRQ0 is not valid, can we arrange for the generic interrupt > infrastructure to always fail it's allocation, and then remove the > utterly unused bloatful irq_desc[0] ? > > Didn't think so since x86 folk would scream. Wait a moment, x86 can > map IRQ0 to some other number for the timer interrupt, just like > other architectures are being forced to map their UART interrupts.
I think, what Russell means, is this: #define is_real_interrupt(irq) ((irq) != NO_IRQ) where the NO_IRQ macro has been introduced a LONG time ago specifically for this purpose, and is conveniently defined on some platforms to (unsigned int)-1 or similar, including asm-powerpc/irq.h. And yes, this has been discussed MANY times. Thanks Guennadi --- Guennadi Liakhovetski
