[PATCH 03/12] irq: use desc->poll_timer for irqpoll

From: Tejun Heo
Date: Sun Jun 13 2010 - 11:34:39 EST


Due to tickless and missing IRQF_IRQPOLL flags, irqpoll has been
broken in many configurations for quite some time. Make irqpoll
global polling use desc->poll_timer instead. It's simpler and more
reliable.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
kernel/irq/spurious.c | 41 +++++------------------------------------
1 files changed, 5 insertions(+), 36 deletions(-)

diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 545f730..fc18a13 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -159,41 +159,6 @@ report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret)
}
}

-static inline int
-try_misrouted_irq(unsigned int irq, struct irq_desc *desc,
- irqreturn_t action_ret)
-{
- struct irqaction *action;
-
- if (irqfixup < IRQFIXUP_MISROUTED)
- return 0;
-
- /* We didn't actually handle the IRQ - see if it was misrouted? */
- if (action_ret == IRQ_NONE)
- return 1;
-
- /*
- * But for IRQFIXUP_POLL we also do it for handled interrupts
- * if they are marked as IRQF_IRQPOLL (or for irq zero, which
- * is the traditional PC timer interrupt.. Legacy)
- */
- if (irqfixup < IRQFIXUP_POLL)
- return 0;
-
- if (!irq)
- return 1;
-
- /*
- * Since we don't get the descriptor lock, "action" can
- * change under us. We don't really care, but we don't
- * want to follow a NULL pointer. So tell the compiler to
- * just load it once by using a barrier.
- */
- action = desc->action;
- barrier();
- return action && (action->flags & IRQF_IRQPOLL);
-}
-
void __note_interrupt(unsigned int irq, struct irq_desc *desc,
irqreturn_t action_ret)
{
@@ -213,7 +178,8 @@ void __note_interrupt(unsigned int irq, struct irq_desc *desc,
report_bad_irq(irq, desc, action_ret);
}

- if (unlikely(try_misrouted_irq(irq, desc, action_ret))) {
+ if (unlikely(irqfixup >= IRQFIXUP_MISROUTED &&
+ action_ret == IRQ_NONE)) {
int ok = misrouted_irq(irq);
if (action_ret == IRQ_NONE)
desc->irqs_unhandled -= ok;
@@ -269,6 +235,9 @@ void irq_poll_action_added(struct irq_desc *desc, struct irqaction *action)
}

raw_spin_unlock_irqrestore(&desc->lock, flags);
+
+ if ((action->flags & IRQF_SHARED) && irqfixup >= IRQFIXUP_POLL)
+ mod_timer(&desc->poll_timer, jiffies + IRQ_POLL_INTV);
}

void irq_poll_action_removed(struct irq_desc *desc, struct irqaction *action)
--
1.6.4.2

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