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genirq: Mark polled irqs and defer the real handler

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With the chip.end() function gone we might run into a situation where
a poll call runs and the real interrupt comes in, sees IRQ_INPROGRESS
and disables the line. That might be a perfect working one, which will
then be masked forever.

So mark them polled while the poll runs. When the real handler sees
IRQ_INPROGRESS it checks the poll flag and waits for the polling to
complete. Add the necessary amount of sanity checks to it to avoid
deadlocks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner
2011-02-07 10:34:30 +01:00
parent d05c65fff0
commit fe200ae48e
4 changed files with 61 additions and 28 deletions
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26
kernel/irq/chip.c
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@@ -448,6 +448,13 @@ out_unlock:
}
EXPORT_SYMBOL_GPL(handle_nested_irq);
static bool irq_check_poll(struct irq_desc *desc)
{
if (!(desc->status & IRQ_POLL_INPROGRESS))
return false;
return irq_wait_for_poll(desc);
}
/**
* handle_simple_irq - Simple and software-decoded IRQs.
* @irq: the interrupt number
@@ -469,7 +476,9 @@ handle_simple_irq(unsigned int irq, struct irq_desc *desc)
raw_spin_lock(&desc->lock);
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out_unlock;
if (!irq_check_poll(desc))
goto out_unlock;
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
kstat_incr_irqs_this_cpu(irq, desc);
@@ -510,7 +519,9 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
mask_ack_irq(desc);
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out_unlock;
if (!irq_check_poll(desc))
goto out_unlock;
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
kstat_incr_irqs_this_cpu(irq, desc);
@@ -558,7 +569,8 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
raw_spin_lock(&desc->lock);
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out;
if (!irq_check_poll(desc))
goto out;
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
kstat_incr_irqs_this_cpu(irq, desc);
@@ -620,9 +632,11 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
*/
if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
!desc->action)) {
desc->status |= (IRQ_PENDING | IRQ_MASKED);
mask_ack_irq(desc);
goto out_unlock;
if (!irq_check_poll(desc)) {
desc->status |= (IRQ_PENDING | IRQ_MASKED);
mask_ack_irq(desc);
goto out_unlock;
}
}
kstat_incr_irqs_this_cpu(irq, desc);