Re: [patch 46/47] powerpc: Use new irq allocator

[Thomas Gleixner]

On Sun, 3 Oct 2010, Thomas Gleixner wrote:

> On Sun, 3 Oct 2010, Eric W. Biederman wrote:
> 
> > Thomas Gleixner <tglx@xxxxxxxxxxxxx> writes:
> > 
> > >> That would make things much cleaner and in fact move one large step
> > >> toward being able to make powerpc virq scheme generic, which seems to be
> > >> a good idea from what I've heard :-)
> > >
> > > Yep.
> > 
> > I'm not certain about making the ppc virq scheme generic.  Maybe it is
> > just my distorted impression but I have the understanding that ppc irq
> > numbers mean nothing and are totally unstable whereas on x86 irq numbers
> > in general are stable (across kernel upgrades and changes in device
> > probe order) and the irq number has a useful hardware meaning.  Which
> > means you don't have to go through several layers of translation tables
> > to figure out which hardware pin you are talking about.
> 
> Nobody is forced to use it, but we have already several instances of
> virq mapping implementations in arch/*. Having a generic
> infrastructure for this makes a ton of sense.

Forgot to say: With MSI and dynamic allocated irqs the stable numbers
are completely meaningless. So where is the point ?

Thanks,

	tglx


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