From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41FDFC433EF for ; Wed, 13 Jul 2022 15:20:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236865AbiGMPUC (ORCPT ); Wed, 13 Jul 2022 11:20:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236820AbiGMPUA (ORCPT ); Wed, 13 Jul 2022 11:20:00 -0400 Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 990463C8CF for ; Wed, 13 Jul 2022 08:19:59 -0700 (PDT) Received: by mail-wm1-x32a.google.com with SMTP id 8-20020a05600c024800b003a2fe343db1so615514wmj.1 for ; Wed, 13 Jul 2022 08:19:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=x6cQzIVXOIBGsoXiuif7G7saQrxwRpZyrgHwFA3owXw=; b=UbfTqu9UK6HYMNNZQE81zT8rSE22hs7tx/XmkR6naxIYHSRGj6AEx6AltM1hsmzR4F 4bXiETy55+RlwNvk1IjEOCCbrBKWjYwh8FJes5Nj5Gtm0KJ0htpOIJcD7Hqwk2zDs7Iq TdthzJ+MRMfxWgMott1HwM2DG2cj/Ltjf6j/wAqI5snSDTfKrvkC9XrwI0qTjTRcvv+c 5LWJTTUyjFR99MZfzZv0TGCrJP0PiIujZlTZZ4o1r1cfo8P2cE8WuqC3pSDEs4JlOAeL YWJ0AJHbxRcc0zRWjx++Lf/SLw0q11YGW/x+ml0SCKTD9TzAh2NljacWhysNuOeW9n9o irzw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=x6cQzIVXOIBGsoXiuif7G7saQrxwRpZyrgHwFA3owXw=; b=CdQ2BS2aTu60nOrAp+/36gAAe3F/BdoWJjdkwHrsEWyTOpegBXejP1L78JsXKLsVSJ x4s65oWPBx1wE2DbtaCDBawT49CnLCq22a28mXKnsthlhHAjCITPrHWkuiH1z9PcxLmS 5mnxER8YlAoW46c4vEF5MwBQtthXy+tPkXvVu/68xrz1vsjtWJoNFWyLCrTDoYCBcMjB 5HXYzoJ0L1kR1/WIXmV3soB61LzRF8Ch9cvgJlTIHU9SQq80HrtX+XiIfXyz3n4vAJGt QUiV+izIYjKFrl0ycwvf65maIBgFm0XjFz26n08TY7LqtzXO+TRV5v60lWdq3BTwaxFr I/Bw== X-Gm-Message-State: AJIora8w8tGbXpdAA1ZkhWn88A49FSEWevdQKF7uTUG00W+rpIkKEa9s 1OQonsTR0cinZ3SyydqheqI= X-Google-Smtp-Source: AGRyM1vdjvXKJQAC8aIpaLRCPxjr+/igY107IqJbiR9fjfmShIfWeDr52ubwhRVrPyxEKfoziD1OXw== X-Received: by 2002:a05:600c:1e20:b0:3a2:e540:17ad with SMTP id ay32-20020a05600c1e2000b003a2e54017admr4151536wmb.205.1657725598094; Wed, 13 Jul 2022 08:19:58 -0700 (PDT) Received: from localhost.localdomain ([46.248.82.114]) by smtp.gmail.com with ESMTPSA id i16-20020a05600c355000b003a2f88b2559sm2329150wmq.44.2022.07.13.08.19.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Jul 2022 08:19:57 -0700 (PDT) From: Uros Bizjak To: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Cc: Uros Bizjak , Takashi Iwai Subject: [PATCH] ALSA: usb-audio: Use atomic_try_cmpxchg in ep_state_update Date: Wed, 13 Jul 2022 17:19:46 +0200 Message-Id: <20220713151946.4743-1-ubizjak@gmail.com> X-Mailer: git-send-email 2.35.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Cc: Takashi Iwai --- 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