Loic Prylli <[email protected]> writes:
I still looking through my copy of the pci specs and so will reply to
that part in a bit.
> To detect a crazy device generating storms of edge interrupts, I guess
> note_interrupt() could be called during this "reentrant detection" if
> masking was made conditional.
Hmm. Something like this?
Only mask it if the irq is disabled, and only disable it if
the user requests it or if note_interrupt decides we are screaming?
void handle_edge_irq(unsigned int irq, struct irq_desc *desc)
{
const unsigned int cpu = smp_processor_id();
spin_lock(&desc->lock);
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
/*
* If we're currently running this IRQ, or its disabled,
* we shouldn't process the IRQ. Mark it pending, handle
* the necessary masking and go out
*/
if (unlikely((desc->status & IRQ_DISABLED) || !desc->action)){
desc->status |= (IRQ_PENDING | IRQ_MASKED);
mask_ack_irq(desc, irq);
goto out_unlock;
}
if (unlikely(desc->status & IRQ_INPROGRESS)) {
desc->status |= IRQ_PENDING;
desc->chip->ack(desc, irq);
note_interrupt(irq, desc, IRQ_NONE /* IRQ_DUP? */);
goto out_unlock;
}
kstat_cpu(cpu).irqs[irq]++;
/* Start handling the irq */
desc->chip->ack(irq);
/* Mark the IRQ currently in progress.*/
desc->status |= IRQ_INPROGRESS;
do {
struct irqaction *action = desc->action;
irqreturn_t action_ret;
if (unlikely(!action)) {
desc->chip->mask(irq);
goto out_unlock;
}
desc->status &= ~IRQ_PENDING;
spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
spin_lock(&desc->lock);
} while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
desc->status &= ~IRQ_INPROGRESS;
out_unlock:
spin_unlock(&desc->lock);
}
Eric
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