Messages in this thread | | | Date | Tue, 1 Mar 2011 15:09:52 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH 3/8] Add a mfd IPUv3 driver |
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On Tue, 1 Mar 2011, Arnd Bergmann wrote:
> On Tuesday 01 March 2011, Sascha Hauer wrote: > > > Taking one step back from this, have you considered making this > > > a regular interrupt controller? That would make the client drivers > > > more standard -- you could define the interrupt numbers as resources > > > of a platform device or in the device tree, for instance. > > > The cost might be more complex code, e.g. when a device requires > > > many interrupts, but I think it will be at least as efficient > > > at run-time, and less surprising for readers and authors of > > > client drivers. > > > > I thought about this, but hesitated to increase NR_IRQS by 463. Do you > > think we should do this instead? > > I think there is a plan to virtualize the interrupt numbers on ARM, > and in that case NR_IRQS becomes rather meaningless. I don't know > exactly how far that effort has come.
Also sparse irqs allows us now to allocate beyond NR_IRQS. With sparse irqs NR_IRQS is pretty meaningless and just gives us an indicator how large the irq space might become, but we allow up to 8k dynamically allocated irqs beyond NR_IRQS, so this should be sufficient for your problem.
Thanks,
tglx
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