diff options
Diffstat (limited to 'include/asm-generic/mutex-xchg.h')
| -rw-r--r-- | include/asm-generic/mutex-xchg.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/asm-generic/mutex-xchg.h b/include/asm-generic/mutex-xchg.h index a6b4a7bd6..3269ec4e1 100644 --- a/include/asm-generic/mutex-xchg.h +++ b/include/asm-generic/mutex-xchg.h @@ -91,8 +91,12 @@ __mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *)) static inline int __mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *)) { - int prev = atomic_xchg_acquire(count, 0); + int prev; + if (atomic_read(count) != 1) + return 0; + + prev = atomic_xchg_acquire(count, 0); if (unlikely(prev < 0)) { /* * The lock was marked contended so we must restore that |