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authorThomas Gleixner <tglx@linutronix.de>2012-11-23 10:08:44 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-02-28 05:38:28 -0800
commita657c66d3ba73cc84201d8fe62adf7e7d97f71df (patch)
tree45c8f867777756ef780ad4db30ff7cf6fcf275f5 /kernel
parent57eb4c95dff59038eb6223dc7696c93b045c4c3f (diff)
genirq: Avoid deadlock in spurious handling
commit e716efde75267eab919cdb2bef5b2cb77f305326 upstream. commit 52553ddf(genirq: fix regression in irqfixup, irqpoll) introduced a potential deadlock by calling the action handler with the irq descriptor lock held. Remove the call and let the handling code run even for an interrupt where only a single action is registered. That matches the goal of the above commit and avoids the deadlock. Document the confusing action = desc->action reload in the handling loop while at it. Reported-and-tested-by: "Wang, Warner" <warner.wang@hp.com> Tested-by: Edward Donovan <edward.donovan@numble.net> Cc: "Wang, Song-Bo (Stoney)" <song-bo.wang@hp.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/irq/spurious.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 611cd6003c4..7b5f012bde9 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -80,13 +80,11 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force)
/*
* All handlers must agree on IRQF_SHARED, so we test just the
- * first. Check for action->next as well.
+ * first.
*/
action = desc->action;
if (!action || !(action->flags & IRQF_SHARED) ||
- (action->flags & __IRQF_TIMER) ||
- (action->handler(irq, action->dev_id) == IRQ_HANDLED) ||
- !action->next)
+ (action->flags & __IRQF_TIMER))
goto out;
/* Already running on another processor */
@@ -104,6 +102,7 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force)
do {
if (handle_irq_event(desc) == IRQ_HANDLED)
ret = IRQ_HANDLED;
+ /* Make sure that there is still a valid action */
action = desc->action;
} while ((desc->istate & IRQS_PENDING) && action);
desc->istate &= ~IRQS_POLL_INPROGRESS;