lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[PATCH] Debug shared irqs

Browse Source 
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>
This commit is contained in:
David Woodhouse
2007-02-12 00:52:00 -08:00
committed by Linus Torvalds
parent f9e4acf3be
commit a304e1b828
2 changed files with 42 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
kernel/irq/manage.c
View File

@@ -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);