Subject: Re: [PATCH] pata_of_platform: fix no irq handling

From: Benjamin Herrenschmidt <[email-masked]>
Date: Tue, 07 Oct 2008 21:04:45 +1100

On Tue, 2008-10-07 at 13:26 +0400, Anton Vorontsov wrote:
> On Tue, Oct 07, 2008 at 10:30:59AM +0900, Tejun Heo wrote:
> > Anton Vorontsov wrote:
> > > On Mon, Oct 06, 2008 at 03:41:19PM -0500, Matt Sealey wrote:
> > >> There is a simple problem with the patch which is that an "IRQ 0" can and does
> > >> actually exist on a bunch of platforms, at least to the best of my knowledge.
> > >>
> > >> Checking for -1 (which means for definite, no irq at all, because it is
> > >> totally unambiguous, as a -1 IRQ numbering is "impossible") is more correct.
> > > 
> > > This was discussed years ago.
> > > 
> > > http://lkml.org/lkml/2005/11/22/159
> > > http://lkml.org/lkml/2005/11/22/227
> > > 
> > 
> > Would this break any existing platforms?
> 
> Nope.
> 
> The driver is only available for PPC platforms.
> 
> As time goes by one can change `depend on PPC_OF' to just `depends on
> OF', so that the driver will be also available for SPARC. And still
> it will work, because SPARC also understands VIRQ0 as invalid VIRQ.
> 

Yup, I agree. I'll pick it up in my next batch.

Cheers,
Ben.