Re: [PATCH] 2.6.18-rt7: PowerPC: fix breakage in threaded fasteoi type IRQ handlers

Ingo Molnar
2006-11-20T16:43:16Z

* Daniel Walker <dwalker@mvista.com> wrote:

> It makes porting to powerpc for instance harder because some
> controllers have ack(), and some don't.. Some have mask(), and some
> don't.. So you end up with what Sergei is doing which is flat out make
> ack == eoi .. Where you have multiple irq chip types each one really
> needs an individual evaluation ..

this isnt really a problem. The current situation is simply hacky,
because right now there's no 'threaded' flow type at all. The x86 code
just moves the code away from fasteoi:

#ifdef CONFIG_PREEMPT_HARDIRQS
set_irq_chip_and_handler_name(irq, &ioapic_chip,
handle_level_irq, "level-threaded");#else
set_irq_chip_and_handler_name(irq, &ioapic_chip,
handle_fasteoi_irq, "fasteoi");
#endif

what should happen is a handle_thread_irq irq-flow handler that will
first mask, and then ack or eoi (whichever callbacks is available), and
thus can and will handle both fasteoi, edge and level irqs.

Ingo