Messages in this thread | | | Date | Wed, 24 Mar 2010 18:44:06 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH 01/10] irq: move some interrupt arch_* functions into struct irq_chip. |
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On Wed, 24 Mar 2010, Ian Campbell wrote:
> On Mon, 2010-03-22 at 10:19 +0000, Thomas Gleixner wrote: > > On Sun, 21 Mar 2010, Yinghai Lu wrote: > > > > > From: Ian Campbell <ian.campbell@citrix.com> > > > > > > Move arch_init_copy_chip_data and arch_free_chip_data into function > > > pointers in struct irq_chip since they operate on irq_desc->chip_data. > > > > Not sure about that. These functions are solely used by x86 and there > > is really no need to generalize them. > > I thought the idea of struct irq_chip was to allow the potential for > multiple IRQ controllers in a system? Given that it seems that struct > irq_desc->chip_data ought to be available for use by whichever struct > irq_chip is managing a given interrupt. At the moment this is not > possible because we step around the abstraction using these arch_* > methods.
Right, but you have exactly _ONE_ irq_chip associated to an irq_desc, but that same irq_chip can be associated to several irq_descs. So irq_desc->data is there to provide data for the irq_chip functions depending on what irq they handle (e.g. base_address ...).
irq_desc->chip_data is set when the irq_chip is assigned to the irq_desc.
So there is no point in having functions in irq_chip to set irq_desc->chip_data.
Thanks,
tglx
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