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authorHans de Goede <hdegoede@redhat.com>2017-04-15 12:08:31 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-03-24 10:57:32 +0100
commit093c265afffb0a91a7611c3bb74d0883731a807b (patch)
tree25f67ca30d0eacbc67ba2d742a32ead6532a7567
parentfad89533e0d5067d38ffd119b4eee5e19d945821 (diff)
downloadlinux-linaro-stable-093c265afffb0a91a7611c3bb74d0883731a807b.tar.gz
genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs
[ Upstream commit 382bd4de61827dbaaf5fb4fb7b1f4be4a86505e7 ] When requesting a shared irq with IRQF_TRIGGER_NONE then the irqaction flags get filled with the trigger type from the irq_data: if (!(new->flags & IRQF_TRIGGER_MASK)) new->flags |= irqd_get_trigger_type(&desc->irq_data); On the first setup_irq() the trigger type in irq_data is NONE when the above code executes, then the irq is started up for the first time and then the actual trigger type gets established, but that's too late to fix up new->flags. When then a second user of the irq requests the irq with IRQF_TRIGGER_NONE its irqaction's triggertype gets set to the actual trigger type and the following check fails: if (!((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) Resulting in the request_irq failing with -EBUSY even though both users requested the irq with IRQF_SHARED | IRQF_TRIGGER_NONE Fix this by comparing the new irqaction's trigger type to the trigger type stored in the irq_data which correctly reflects the actual trigger type being used for the irq. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/20170415100831.17073-1-hdegoede@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--kernel/irq/manage.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index e7ef539c56d9..5f23a04789db 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1058,8 +1058,10 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
* set the trigger type must match. Also all must
* agree on ONESHOT.
*/
+ unsigned int oldtype = irqd_get_trigger_type(&desc->irq_data);
+
if (!((old->flags & new->flags) & IRQF_SHARED) ||
- ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
+ (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
((old->flags ^ new->flags) & IRQF_ONESHOT))
goto mismatch;