[PATCH 046/145] genirq: Fix can_request_irq() for IRQs without an action

From: Kamal Mostafa
Date: Wed Jul 17 2013 - 18:59:59 EST


3.8.13.5 -stable review patch. If anyone has any objections, please let me know.

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

From: Ben Hutchings <ben@xxxxxxxxxxxxxxx>

commit 2779db8d37d4b542d9ca2575f5f178dbeaca6c86 upstream.

Commit 02725e7471b8 ('genirq: Use irq_get/put functions'),
inadvertently changed can_request_irq() to return 0 for IRQs that have
no action. This causes pcibios_lookup_irq() to select only IRQs that
already have an action with IRQF_SHARED set, or to fail if there are
none. Change can_request_irq() to return 1 for IRQs that have no
action (if the first two conditions are met).

Reported-by: Bjarni Ingi Gislason <bjarniig@xxxxxxxxx>
Tested-by: Bjarni Ingi Gislason <bjarniig@xxxxxxxxx> (against 3.2)
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Cc: 709647@xxxxxxxxxxxxxxx
Link: http://bugs.debian.org/709647
Link: http://lkml.kernel.org/r/1372383630.23847.40.camel@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
kernel/irq/manage.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index e49a288..a9302d0 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -554,9 +554,9 @@ int can_request_irq(unsigned int irq, unsigned long irqflags)
return 0;

if (irq_settings_can_request(desc)) {
- if (desc->action)
- if (irqflags & desc->action->flags & IRQF_SHARED)
- canrequest =1;
+ if (!desc->action ||
+ irqflags & desc->action->flags & IRQF_SHARED)
+ canrequest = 1;
}
irq_put_desc_unlock(desc, flags);
return canrequest;
--
1.8.1.2

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