On Mon, 2011-12-05 at 18:45 +0000, Alan Cox wrote: > > But as you illustrated, there is a large number of drivers that already > > assume no IRQ is < 0, even if they don't use any IRQ #0 themselves. > > That is a much bigger problem to fix. > > And a much larger number assuming the reverse is true which are hiding > potential bugs on ARM. > > Looking at the serial stuff the best checks appear to be looking at > "irq", "-1" and NO_IRQ. > > For migration stuff that's doing broken things like > > if (irq < 0) > > can be changed to > > if (irq <= 0) > > and that can be done before NO_IRQ itself is nailed on ARM and PA-RISC. To be honest, we don't care very much. Parisc interrupts are cascading and mostly software assigned (except our EIEM which we keep internal). We use a base offset at 16 or 64 (depending on GSC presence or not) so IRQs 0-15 aren't legal on parisc either (we frob some of the hard coded ISA interrupts on the WAX eisa bus). We use NO_IRQ as an IRQ assignment error return and that's about it (and that error shouldn't ever really occur). James -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html