genirq: Don't allow per cpu interrupts to be suspended
Marc Zyngier [Wed, 16 Nov 2011 12:27:39 +0000 (12:27 +0000)]
The power management functions related to interrupts do not know
(yet) about per-cpu interrupts and end up calling the wrong
low-level methods to enable/disable interrupts.

This leads to all kind of interesting issues (action taken on one
CPU only, updating a refcount which is not used otherwise...).

The workaround for the time being is simply to flag these interrupts
with IRQF_NO_SUSPEND. At least on ARM, these interrupts are actually
dealt with at the architecture level.

Reported-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1321446459-31409-1-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

kernel/irq/manage.c

index 67ce837..0e2b179 100644 (file)
@@ -1596,7 +1596,7 @@ int request_percpu_irq(unsigned int irq, irq_handler_t handler,
                return -ENOMEM;
 
        action->handler = handler;
-       action->flags = IRQF_PERCPU;
+       action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
        action->name = devname;
        action->percpu_dev_id = dev_id;