On Mon, Jun 15, 2009 at 12:12:07AM +0100, Alan Cox wrote: > > > + if (!uioinfo->irq) > > > + uioinfo->irq = UIO_IRQ_NONE; > > > > Please don't do this. It's inconsistent if all other UIO drivers require > > people to use UIO_IRQ_NONE and you also allow zero. UIO_IRQ_NONE was > > introduced because 0 may be a legal interrupt number on some platforms. > > Zero is not a valid IRQ number in the kernel (except in arch specific > depths). IRQ numbers are also *unsigned* so -1 isn't a safe definition.
The above uioinfo->irq is a signed long. > > Zero means no IRQ. If any old UIO code is assuming otherwise it wants > fixing. It doesn't. It won't complain about IRQ 0 and will pass it on to request_irq, which will probably fail if it is as you say. I did it that way because I saw IRQ 0 in /proc/interrupts on every PC... > > It is the job of the platform to map a physical IRQ 0 to some other > representation if it exists outside of arch specific code. Funny. > This was > decided some years ago and a large part of the kernel simply doesn't > support any notion of a real IRQ 0. Can you tell me the reason for that decision or point me to some ml archive? Thanks, Hans > > Alan _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
