Re: irq domain hierarchy vs. chaining w/ PCI MSI-X...

From: Thomas Gleixner
Date: Mon Jan 30 2017 - 08:33:54 EST


On Fri, 13 Jan 2017, David Daney wrote:
> At the point where the handle_*_irq() functions call handle_irq_event(), we
> need to 9optionally) do something both immediately before and after the call
> to handle_irq_event().
>
> In irq_chip add a function:
>
> void (*irq_handle)(struct irq_data *data, struct irq_desc *desc);
>
> Really this is the per irq_chip flow handler.
>
> Then in handle_fasteoi_irq() and probably the other flow handlers as well:
>
> .
> .
> .
> if (chip->irq_handle)
> chip->irq_handle(&desc->irq_data, desc);
> else
> handle_irq_event(desc);
> .
> .
> .
>
> Those 4 lines of code could be factored out into a helper function in chip.c


And why don't you just write a flow handler function which does exactly
what you need instead of adding more conditionals into all hotpath
functions?

Thanks,

tglx