Use atomic_try_cmpxchg instead of atomic_cmpxchg (*ptr, old, new) == old in ep_state_update. x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg).
No functional change intended.
Signed-off-by: Uros Bizjak ubizjak@gmail.com Cc: Takashi Iwai tiwai@suse.de --- sound/usb/endpoint.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c index f9c921683948..0d7b73bf7945 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -133,7 +133,7 @@ static inline bool ep_state_running(struct snd_usb_endpoint *ep)
static inline bool ep_state_update(struct snd_usb_endpoint *ep, int old, int new) { - return atomic_cmpxchg(&ep->state, old, new) == old; + return atomic_try_cmpxchg(&ep->state, &old, new); }
/**