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genirq: Do not poll disabled, percpu and timer interrupts

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There is no point in polling disabled lines.

percpu does not make sense at all because we only poll on the cpu
we're currently running on. Also polling per_cpu interrupts is racy as
hell. The handler runs without locking so we might get a huge
surprise.

If the timer interrupt needs polling, then we wont get there anyway.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner 2011-02-07 09:52:27 +01:00
parent fa27271bc8
commit c7259cd7af
1 changed files with 26 additions and 14 deletions
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40
kernel/irq/spurious.c
View file

@ -25,30 +25,42 @@ static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0);
/*
* Recovery handler for misrouted interrupts.
*/
static int try_one_irq(int irq, struct irq_desc *desc)
static int try_one_irq(int irq, struct irq_desc *desc, bool force)
{
struct irqaction *action;
int ok = 0, work = 0;
raw_spin_lock(&desc->lock);
/* PER_CPU and nested thread interrupts are never polled */
if (desc->status & (IRQ_PER_CPU | IRQ_NESTED_THREAD))
goto out;
/*
* Do not poll disabled interrupts unless the spurious
* disabled poller asks explicitely.
*/
if ((desc->status & IRQ_DISABLED) && !force)
goto out;
/*
* All handlers must agree on IRQF_SHARED, so we test just the
* first. Check for action->next as well.
*/
action = desc->action;
if (!action || !(action->flags & IRQF_SHARED) ||
(action->flags & __IRQF_TIMER) || !action->next)
goto out;
/* Already running on another processor */
if (desc->status & IRQ_INPROGRESS) {
/*
* Already running: If it is shared get the other
* CPU to go looking for our mystery interrupt too
*/
if (desc->action && (desc->action->flags & IRQF_SHARED))
desc->status |= IRQ_PENDING;
raw_spin_unlock(&desc->lock);
return ok;
}
/*
* All handlers must agree on IRQF_SHARED, so we test just the
* first. Check for action->next as well.
*/
action = desc->action;
if (!action || !(action->flags & IRQF_SHARED) || !action->next)
desc->status |= IRQ_PENDING;
goto out;
}
/* Honour the normal IRQ locking */
desc->status |= IRQ_INPROGRESS;
@ -87,7 +99,7 @@ static int misrouted_irq(int irq)
if (i == irq) /* Already tried */
continue;
if (try_one_irq(i, desc))
if (try_one_irq(i, desc, false))
ok = 1;
}
/* So the caller can adjust the irq error counts */
@ -112,7 +124,7 @@ static void poll_spurious_irqs(unsigned long dummy)
continue;
local_irq_disable();
try_one_irq(i, desc);
try_one_irq(i, desc, true);
local_irq_enable();
}