Re: [PATCHv2 02/10] ARM: vic: MULTI_IRQ_HANDLER handler

[Russell King - ARM Linux <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>]

On Thu, Nov 03, 2011 at 02:00:15PM +0100, Linus Walleij wrote:
> On Thu, Nov 3, 2011 at 1:51 PM, Russell King - ARM Linux
> <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org> wrote:
> 
> >        stat = readl_relaxed(vic->base + VIC_IRQ_STATUS);
> >        while (stat) {
> >                while (stat) {
> >                        irq = ffs(stat) - 1;
> >                        stat &= ~(1 << irq);
> >                        handle_irq(irq);
> >                }
> >                stat = readl_relaxed(vic->base + VIC_IRQ_STATUS);
> >        }
> >
> > This ensures that we process all interrupts found pending before we
> > re-check for any new interrupts pending.  Arguably this is a much
> > fairer implementation (and may mean if things get irrevokably stuck,
> > things like sysrq via the console uart may still work.)
> 
> I really like the looks of this, Jamie can you do it like that?
> 
> Maybe some smallish comment about what's going on can be
> good for future generations reading that code...

Bear in mind that it gets a little more complex when you have more
than one VIC, because the outer loop should be across all VICs.