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

Ingo Molnar
2006-11-20T19:11:18Z

* Sergei Shtylyov <sshtylyov@ru.mvista.com> wrote:

> >-#else
> >- set_irq_chip_and_handler_name(irq, &ioapic_chip,
> >- handle_edge_irq, "edge");
> >-#endif
> >+ handle_edge_irq, "edge");
>
> Hm, why force edge flow on edge-triggered IRQs?

it doesnt do that. This, ontop of -rt4 restores it to the vanilla arch
code.

> > if (desc->chip->mask_ack)
> > desc->chip->mask_ack(irq);
> > else {
> >- desc->chip->mask(irq);
> >- desc->chip->ack(irq);
> >+ if (desc->chip->mask)
> >+ desc->chip->mask(irq);
> >+ if (desc->chip->mask)
> >+ desc->chip->ack(irq);
> > }
> > }
>
> Hmm, that just won't do for PPC threaded fasteoi flows! What you'll
> get is a threaded IRQ with EOI *never ever* issued, unless my PPC
> patch is also in...

ok, how about the patch below in addition?

Ingo

Index: linux/kernel/irq/chip.c
===================================================================
--- linux.orig/kernel/irq/chip.c
+++ linux/kernel/irq/chip.c
@@ -396,7 +398,7 @@ handle_fasteoi_irq(unsigned int irq, str
*/
if (redirect_hardirq(desc)) {
mask_ack_irq(desc, irq);
- goto out_unlock;
+ goto out;
}

desc->status &= ~IRQ_PENDING;