Commit 89422df9 authored by Uros Bizjak's avatar Uros Bizjak Committed by Takashi Iwai

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: default avatarUros Bizjak <ubizjak@gmail.com>
Link: https://lore.kernel.org/r/20220713151946.4743-1-ubizjak@gmail.comSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 281dee67
......@@ -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);
}
/**
......
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