[PATCH] genirq: Give warning when setup an already-setup non-shared irq

[Chuansheng Liu <chuansheng.liu@intel.com>]

Meet the case when the request_threaded_irq() with the same irq
is called twice continually, get the below mismatch info:
"IRQ handler type mismatch for IRQ 323"

Here give a right warning that like below:
"Trying to setup already-setup non-shared IRQ 323"

Signed-off-by: liu chuansheng <chuansheng.liu@intel.com>
---
 kernel/irq/manage.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index e49a288..6802ce1 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -999,6 +999,16 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 	old_ptr = &desc->action;
 	old = *old_ptr;
 	if (old) {
+		/* Give warning when setup an irq which has been setup
+		 * already.
+		 */
+		if (!(old->flags & IRQF_SHARED)) {
+			ret = -EINVAL;
+			WARN(1, "Trying to setup already-setup non-shared IRQ %d\n",
+				irq);
+			goto out_mask;
+		}
+
 		/*
 		 * Can't share interrupts unless both agree to and are
 		 * the same type (level, edge, polarity). So both flag
-- 
1.7.0.4