diff options
| author | David Woodhouse <dwmw2@infradead.org> | 2007-02-12 00:52:00 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-12 09:48:28 -0800 |
| commit | a304e1b82808904c561b7b149b467e338c53fcce (patch) | |
| tree | 068b68c37f6f11de116288886eb211f267d790f7 | |
| parent | f9e4acf3befd3b2903e01b3ef1bd344f03299826 (diff) | |
| download | linux-a304e1b82808904c561b7b149b467e338c53fcce.tar.bz2 | |
[PATCH] Debug shared irqs
Drivers registering IRQ handlers with SA_SHIRQ really ought to be able to
handle an interrupt happening before request_irq() returns. They also
ought to be able to handle an interrupt happening during the start of their
call to free_irq(). Let's test that hypothesis....
[bunk@stusta.de: Kconfig fixes]
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | kernel/irq/manage.c | 33 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 9 |
2 files changed, 42 insertions, 0 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 8b961adc3bd2..400b12a63649 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -357,6 +357,7 @@ void free_irq(unsigned int irq, void *dev_id) struct irq_desc *desc; struct irqaction **p; unsigned long flags; + irqreturn_t (*handler)(int, void *) = NULL; WARN_ON(in_interrupt()); if (irq >= NR_IRQS) @@ -396,6 +397,8 @@ void free_irq(unsigned int irq, void *dev_id) /* Make sure it's not being used on another CPU */ synchronize_irq(irq); + if (action->flags & IRQF_SHARED) + handler = action->handler; kfree(action); return; } @@ -403,6 +406,17 @@ void free_irq(unsigned int irq, void *dev_id) spin_unlock_irqrestore(&desc->lock, flags); return; } +#ifdef CONFIG_DEBUG_SHIRQ + if (handler) { + /* + * It's a shared IRQ -- the driver ought to be prepared for it + * to happen even now it's being freed, so let's make sure.... + * We do this after actually deregistering it, to make sure that + * a 'real' IRQ doesn't run in parallel with our fake + */ + handler(irq, dev_id); + } +#endif } EXPORT_SYMBOL(free_irq); @@ -475,6 +489,25 @@ int request_irq(unsigned int irq, irq_handler_t handler, select_smp_affinity(irq); +#ifdef CONFIG_DEBUG_SHIRQ + if (irqflags & IRQF_SHARED) { + /* + * It's a shared IRQ -- the driver ought to be prepared for it + * to happen immediately, so let's make sure.... + * We do this before actually registering it, to make sure that + * a 'real' IRQ doesn't run in parallel with our fake + */ + if (irqflags & IRQF_DISABLED) { + unsigned long flags; + + local_irq_save(flags); + handler(irq, dev_id); + local_irq_restore(flags); + } else + handler(irq, dev_id); + } +#endif + retval = setup_irq(irq, action); if (retval) kfree(action); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 356a5ab8279c..63f04c15e6f5 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -77,6 +77,15 @@ config DEBUG_KERNEL Say Y here if you are developing drivers or trying to debug and identify kernel problems. +config DEBUG_SHIRQ + bool "Debug shared IRQ handlers" + depends on DEBUG_KERNEL && GENERIC_HARDIRQS + help + Enable this to generate a spurious interrupt as soon as a shared + interrupt handler is registered, and just before one is deregistered. + Drivers ought to be able to handle interrupts coming in at those + points; some don't and need to be caught. + config LOG_BUF_SHIFT int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL range 12 21 |