From patchwork Sun Jul 26 10:58:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julia Lawall X-Patchwork-Id: 11685677 X-Patchwork-Delegate: kvalo@adurom.com Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B7E4A913 for ; Sun, 26 Jul 2020 11:40:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A8EB520714 for ; Sun, 26 Jul 2020 11:40:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728087AbgGZLkA (ORCPT ); Sun, 26 Jul 2020 07:40:00 -0400 Received: from mail3-relais-sop.national.inria.fr ([192.134.164.104]:32833 "EHLO mail3-relais-sop.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728014AbgGZLj5 (ORCPT ); Sun, 26 Jul 2020 07:39:57 -0400 X-IronPort-AV: E=Sophos;i="5.75,398,1589234400"; d="scan'208";a="355309549" Received: from palace.rsr.lip6.fr (HELO palace.lip6.fr) ([132.227.105.202]) by mail3-relais-sop.national.inria.fr with ESMTP/TLS/AES256-SHA256; 26 Jul 2020 13:39:48 +0200 From: Julia Lawall To: Kalle Valo Cc: kernel-janitors@vger.kernel.org, "David S. Miller" , Jakub Kicinski , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 7/7] ath: drop unnecessary list_empty Date: Sun, 26 Jul 2020 12:58:32 +0200 Message-Id: <1595761112-11003-8-git-send-email-Julia.Lawall@inria.fr> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1595761112-11003-1-git-send-email-Julia.Lawall@inria.fr> References: <1595761112-11003-1-git-send-email-Julia.Lawall@inria.fr> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org list_for_each_entry{_safe} is able to handle an empty list. The only effect of avoiding the loop is not initializing the index variable. Drop list_empty tests in cases where these variables are not used. Note that list_for_each_entry{_safe} is defined in terms of list_first_entry, which indicates that it should not be used on an empty list. But in list_for_each_entry{_safe}, the element obtained by list_first_entry is not really accessed, only the address of its list_head field is compared to the address of the list head, so the list_first_entry is safe. The semantic patch that makes this change for the list_for_each_entry case is as follows: (http://coccinelle.lip6.fr/) @@ expression x,e; statement S; identifier i; @@ -if (!(list_empty(x))) list_for_each_entry(i,x,...) S ... when != i ? i = e Signed-off-by: Julia Lawall --- drivers/net/wireless/ath/dfs_pattern_detector.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/net/wireless/ath/dfs_pattern_detector.c b/drivers/net/wireless/ath/dfs_pattern_detector.c index a274eb0..0813473 100644 --- a/drivers/net/wireless/ath/dfs_pattern_detector.c +++ b/drivers/net/wireless/ath/dfs_pattern_detector.c @@ -253,17 +253,15 @@ static void channel_detector_exit(struct dfs_pattern_detector *dpd, static void dpd_reset(struct dfs_pattern_detector *dpd) { struct channel_detector *cd; - if (!list_empty(&dpd->channel_detectors)) - list_for_each_entry(cd, &dpd->channel_detectors, head) - channel_detector_reset(dpd, cd); + list_for_each_entry(cd, &dpd->channel_detectors, head) + channel_detector_reset(dpd, cd); } static void dpd_exit(struct dfs_pattern_detector *dpd) { struct channel_detector *cd, *cd0; - if (!list_empty(&dpd->channel_detectors)) - list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head) - channel_detector_exit(dpd, cd); + list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head) + channel_detector_exit(dpd, cd); kfree(dpd); } @@ -331,9 +329,8 @@ static bool dpd_set_domain(struct dfs_pattern_detector *dpd, return false; /* delete all channel detectors for previous DFS domain */ - if (!list_empty(&dpd->channel_detectors)) - list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head) - channel_detector_exit(dpd, cd); + list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head) + channel_detector_exit(dpd, cd); dpd->radar_spec = rt->radar_types; dpd->num_radar_types = rt->num_radar_types;