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authorUros Bizjak2022-07-13 17:19:46 +0200
committerTakashi Iwai2022-07-14 10:49:25 +0200
commit89422df9548002adfffb73799cebe4909cfc8902 (patch)
treed2a4f11902e5d2ab4bb8872e6208d88d18adc873
parent281dee6707a869e0f40cac81b6b65c703192aa9d (diff)
ALSA: usb-audio: Use atomic_try_cmpxchg in ep_state_update
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> Link: https://lore.kernel.org/r/20220713151946.4743-1-ubizjak@gmail.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--sound/usb/endpoint.c2
1 files changed, 1 insertions, 1 deletions
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);
}
/**