On Sat, Dec 03, 2011 at 10:12:53AM +1100, Benjamin Herrenschmidt wrote: > On Fri, 2011-12-02 at 11:28 -0800, Linus Torvalds wrote: > > On Fri, Dec 2, 2011 at 11:26 AM, Dave Martin <dave.martin@xxxxxxxxxx> wrote: > > > > > > This is now broken on ARM where, for good or bad, NO_IRQ currently is > > > used and is -1. > > > > > > How do we resolve it? If we are ready to eliminate NO_IRQ from > > > drivers/of/irq.c (or indeed, all code that uses it) and just use 0 for > > > that case, we should surely just do it... but I'm not confident I can > > > judge on that. > > > > Just stop using NO_IRQ. First in drivers/of/irq.c, then in any drivers > > as you notice breakage. > > Agreed. In fact the whole hack in drivers/of/irq.c was to accomodate ARM > which still uses -1, powerpc changed to 0 a long time ago. > > Now that we have a generic remapper between HW and "linux" IRQ numbers, > there is no reason to stick to -1 even on ARM. > > > Don't *change* NO_IRQ to zero (that whole #define is broken - leave it > > around as a marker of brokenness), just start removing it from all the > > ARM drivers that use the OF infrastructure. Which is presumably not > > all that many yet. > > > > So whenever you find breakage, the fix now is to just remove NO_IRQ > > tests, and replace them with "!irq". > Russell, do you know whether it would make sense to set a timeline for removing NO_IRQ from ARM platforms and migrating to 0 for the no-interrupt case? I'm assuming that this mainly involves migrating existing hard-wired code that deals with interrupt numbers to use irq domains. I worry that if we just change the convention for the OF case, we'll end up with OF-ised platform drivers which have to deal with a different no- irq convention depending on whether they are probed as platform drivers or through the OF framework ... and these ported or semi-ported drivers will be intermixed with unported drivers, confusing maintainers. If board code starts initialising platform data for non-OF-ised platform drivers based on IRQ numbers fetched via the OF code, things will get even more confused... Cheers ---Dave -- 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
