From: Greg KH on
2.6.33-stable review patch. If anyone has any objections, please let us know.

------------------

From: Johannes Berg <johannes(a)sipsolutions.net>

commit 3cd8519248e9e17d982c6fab0f1a89bca6feb49a upstream.

When SPARSE_IRQ is set, irq_to_desc() can
return NULL. While the code here has a
check for NULL, it's not really correct.
Fix it by separating the check for it.

This fixes CPU hot unplug for me.

Reported-by: Alastair Bridgewater <alastair.bridgewater(a)gmail.com>
Signed-off-by: Johannes Berg <johannes(a)sipsolutions.net>
Signed-off-by: Benjamin Herrenschmidt <benh(a)kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de>

---
arch/powerpc/kernel/irq.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -247,7 +247,10 @@ void fixup_irqs(cpumask_t map)
cpumask_t mask;

desc = irq_to_desc(irq);
- if (desc && desc->status & IRQ_PER_CPU)
+ if (!desc)
+ continue;
+
+ if (desc->status & IRQ_PER_CPU)
continue;

cpumask_and(&mask, desc->affinity, &map);


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/