Re: [Patch V3 19/37] x86, irq: introduce mechanisms to support dynamically allocate IRQ for IOAPIC

[Thomas Gleixner]

On Wed, 28 May 2014, Thomas Gleixner wrote:
> On Wed, 28 May 2014, Jiang Liu wrote:
> > This is used to work around special non-ISA interrupts with GSI below
> > NR_IRQS_LEGACY. The original code for the special case is:
> > /*
> >  * Provide an identity mapping of gsi == irq except on truly
> >  * weird platforms that have non isa irqs in the first 16 gsis.
> >  */
> > return gsi >= NR_IRQS_LEGACY ? gsi : gsi_top + gsi;
> 
> That looks really, really wrong. What's wrong with assigning that irq
> irq number on those platforms?
> 
> The weird stuff is SFI and devicetree, if I understand your code
> correctly.
> 
> So if those platforms do not have actual legacy irqs, what's wrong
> with giving out the legacy numbers?

Though if it's a real issue, we can simply mark the ioapic on those
devices as DYNAMIC and avoid that whole magic.

Thanks,

	tglx
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