diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2012-11-23 10:08:44 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-03-06 03:22:34 +0000 |
| commit | 9771304decd27e25593b1c3f6cd80a91c1c8f219 (patch) | |
| tree | 83f8a6c3d43f1b3f6d8c181bbec054d70d9f73f6 /kernel | |
| parent | 3208ee7f73115f8a92912ad05a15b97da41fae58 (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: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/irq/spurious.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index dc813a948be2..63633a320fb7 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; |