Merge branches 'clockevents/4.4-fixes' and 'clockevents/4.5-fixes' of http://git.linaro.org/people/daniel.lezcano/linux into timers/urgent

Pull in fixes from Daniel Lezcano:

 - Fix the vt8500 timer leading to a system lock up when dealing with too
   small delta (Roman Volkov)

 - Select the CLKSRC_MMIO when the fsl_ftm_timer is enabled with COMPILE_TEST
   (Daniel Lezcano)

 - Prevent to compile timers using the 'iomem' API when the architecture has
   not HAS_IOMEM set (Richard Weinberger)

1 files changed, 5 insertions, 3 deletions

diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index d092a0c9c2d4..05a37857ab55 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -93,10 +93,12 @@ bool osq_lock(struct optimistic_spin_queue *lock)
 	node->cpu = curr;
 
 	/*
-	 * ACQUIRE semantics, pairs with corresponding RELEASE
-	 * in unlock() uncontended, or fastpath.
+	 * We need both ACQUIRE (pairs with corresponding RELEASE in
+	 * unlock() uncontended, or fastpath) and RELEASE (to publish
+	 * the node fields we just initialised) semantics when updating
+	 * the lock tail.
 	 */
-	old = atomic_xchg_acquire(&lock->tail, curr);
+	old = atomic_xchg(&lock->tail, curr);
 	if (old == OSQ_UNLOCKED_VAL)
 		return true;