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| author | Uros Bizjak <ubizjak@gmail.com> | 2022-07-13 18:19:46 +0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2022-07-14 11:49:25 +0300 |
| commit | 89422df9548002adfffb73799cebe4909cfc8902 (patch) | |
| tree | d2a4f11902e5d2ab4bb8872e6208d88d18adc873 | |
| parent | 281dee6707a869e0f40cac81b6b65c703192aa9d (diff) | |
| download | linux-89422df9548002adfffb73799cebe4909cfc8902.tar.xz | |
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.c | 2 |
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); } /** |