On Wed, 24 Mar 2010, Ian Campbell wrote:

On Mon, 2010-03-22 at 10:19 +0000, Thomas Gleixner wrote:

quoted

On Sun, 21 Mar 2010, Yinghai Lu wrote:

quoted

From: Ian Campbell <redacted>

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