From: Uros Bizjak <ubizjak@gmail.com>
To: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
Cc: Uros Bizjak <ubizjak@gmail.com>, Takashi Iwai <tiwai@suse.de>
Subject: [PATCH] ALSA: usb-audio: Use atomic_try_cmpxchg in ep_state_update
Date: Wed, 13 Jul 2022 17:19:46 +0200 [thread overview]
Message-ID: <20220713151946.4743-1-ubizjak@gmail.com> (raw)
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);
}
/**
--
2.35.3
next reply other threads:[~2022-07-13 15:20 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-13 15:19 Uros Bizjak [this message]
2022-07-14 8:49 ` Takashi Iwai
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220713151946.4743-1-ubizjak@gmail.com \
--to=ubizjak@gmail.com \
--cc=alsa-devel@alsa-project.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tiwai@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®