diff options
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/irq/manage.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 80eab7a04205..1f314221d534 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c | |||
@@ -29,12 +29,28 @@ | |||
29 | void synchronize_irq(unsigned int irq) | 29 | void synchronize_irq(unsigned int irq) |
30 | { | 30 | { |
31 | struct irq_desc *desc = irq_desc + irq; | 31 | struct irq_desc *desc = irq_desc + irq; |
32 | unsigned int status; | ||
32 | 33 | ||
33 | if (irq >= NR_IRQS) | 34 | if (irq >= NR_IRQS) |
34 | return; | 35 | return; |
35 | 36 | ||
36 | while (desc->status & IRQ_INPROGRESS) | 37 | do { |
37 | cpu_relax(); | 38 | unsigned long flags; |
39 | |||
40 | /* | ||
41 | * Wait until we're out of the critical section. This might | ||
42 | * give the wrong answer due to the lack of memory barriers. | ||
43 | */ | ||
44 | while (desc->status & IRQ_INPROGRESS) | ||
45 | cpu_relax(); | ||
46 | |||
47 | /* Ok, that indicated we're done: double-check carefully. */ | ||
48 | spin_lock_irqsave(&desc->lock, flags); | ||
49 | status = desc->status; | ||
50 | spin_unlock_irqrestore(&desc->lock, flags); | ||
51 | |||
52 | /* Oops, that failed? */ | ||
53 | } while (status & IRQ_INPROGRESS); | ||
38 | } | 54 | } |
39 | EXPORT_SYMBOL(synchronize_irq); | 55 | EXPORT_SYMBOL(synchronize_irq); |
40 | 56 | ||