[PATCH v2 18/26] genirq: Bail out early in free_desc()

Yinghai Lu
2013-02-08T19:29:00Z

We pre-reserve irq range for hot-added ioapic, and later only
some are used via realloc.
So during hot-remove, we need to clear bits in allocated_irqs
for both case.

Check if the irq_desc is there at first, and bail out early if
irq_desc is not allocated yet.

So we can use irq_free_descs to clear allocated_irqs bits for
preserved irqs.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
kernel/irq/irqdesc.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index b48f65b..32f099e 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -170,6 +170,9 @@ static void free_desc(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);

+ if (!desc)
+ return;
+
unregister_irq_proc(irq, desc);

mutex_lock(&sparse_irq_lock);
--
1.7.10.4