From e35f309a9eb6078f3d09d042b9ebcff7612d9398 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 2 Dec 2015 11:34:07 +0100
Subject: [PATCH 128/283] rtmutex: trylock is okay on -RT

non-RT kernel could deadlock on rt_mutex_trylock() in softirq context. On
-RT we don't run softirqs in IRQ context but in thread context so it is
not a issue here.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 kernel/locking/rtmutex.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 9562aaa2afdc..72abe7c121fa 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1583,7 +1583,11 @@ int __sched rt_mutex_trylock(struct rt_mutex *lock)
 {
 	int ret;
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (WARN_ON_ONCE(in_irq() || in_nmi()))
+#else
 	if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq()))
+#endif
 		return 0;
 
 	ret = rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
-- 
2.20.1

