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 47F43C433EF for ; Sun, 20 Mar 2022 00:47:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244497AbiCTAsz (ORCPT ); Sat, 19 Mar 2022 20:48:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237020AbiCTAsv (ORCPT ); Sat, 19 Mar 2022 20:48:51 -0400 Received: from mail-ej1-x62d.google.com (mail-ej1-x62d.google.com [IPv6:2a00:1450:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88E25241A0A; Sat, 19 Mar 2022 17:47:29 -0700 (PDT) Received: by mail-ej1-x62d.google.com with SMTP id bi12so23654201ejb.3; Sat, 19 Mar 2022 17:47:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=0ifyIt4w3ru4kSUncv7WDTsjeoxWtuh4NygTEp+o10k=; b=JS2ve3DrBfAHO2P2Bv3CJUr8wZE1QGvOPf3jTnTHJlshxFiFtst86yTCxrkHvAo0Bq KlxwJAcYZ2SXlDA9dlY7yZrlhh2WBVmlsIECnw8BB1e+YwBzrOd6dsbDdd4Z2GxC1y5o /xgjlBb69i+8WBpXUyoSkGwTkIFOc5RR/8hobCPg7/XOwEq5zjwhMy5b+Z3Nr+NZjmvu kQXtsSROEsmu8Kb4bi6inmo7/AkIqY2kFvrrsjitEQuM5DtE14S0SnZly7dyjh+V3q5t p+jQ4KtUnTTzYioIR7Y3+jYpwde1h9Qibs/fM8dwLBMZajmwzBYrpxgeoFsyPQvY6HtI LpeQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=0ifyIt4w3ru4kSUncv7WDTsjeoxWtuh4NygTEp+o10k=; b=sPx+82hO9ZX9qJkkzjSdk1Yz7rnMKB9NzwsmcHL4J6qSIQ9QdEgOtwaU1tambu3+D5 eUI/KEVmYzmWy5+QlH8Yl4TfnuBKOBYNTTokfsYQliqZ4FGNVrEGLq33Dzf0iK36rgaQ 0vQhUNDZKgFWznn1JdOvZCPrQ7bAVUy2rs5K1ipNKx7eBqskZYpm9ZExx8bPREHHpCtT KTatBEpEVnn2CROdbN0VUJTGL/gph4VrlM5WmxYUEd5jmf9PXdCVlXcI3vHI51f/ixvf GPAA/BVwyifeOnRRdqcuDuBo0UoQ/4SLFAMgdoQk5iV3lksmZeGmrtmEHrTL+kvdlkOg k72Q== X-Gm-Message-State: AOAM530S6QPtkib7k+mB8T+efIo/h9sxjIKv5zrvC5dyLjpdl66ZnkA4 gaT8D2GfqbabRmA+hBij1CM= X-Google-Smtp-Source: ABdhPJwRZWqRBGortOGDtAQnykWS4EycPTH+HTz7A18lAY7FNnk+WBZhAEFGa6roBtwOKTHFFOB2qg== X-Received: by 2002:a17:907:a42c:b0:6df:e64b:ed6e with SMTP id sg44-20020a170907a42c00b006dfe64bed6emr3082864ejc.284.1647737247965; Sat, 19 Mar 2022 17:47:27 -0700 (PDT) Received: from smtpclient.apple (i130160.upc-i.chello.nl. [62.195.130.160]) by smtp.gmail.com with ESMTPSA id fx3-20020a170906b74300b006daecedee44sm5301881ejb.220.2022.03.19.17.47.27 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sat, 19 Mar 2022 17:47:27 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 15.0 \(3693.60.0.1.1\)) Subject: Re: [PATCH] cw1200: remove an unneeded NULL check on list iterator From: Jakob Koschel In-Reply-To: <20220319063800.28791-1-xiam0nd.tong@gmail.com> Date: Sun, 20 Mar 2022 01:47:26 +0100 Cc: pizza@shaftnet.org, kvalo@kernel.org, davem@davemloft.net, kuba@kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: References: <20220319063800.28791-1-xiam0nd.tong@gmail.com> To: Xiaomeng Tong X-Mailer: Apple Mail (2.3693.60.0.1.1) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On 19. Mar 2022, at 07:38, Xiaomeng Tong = wrote: >=20 > The list iterator 'item' is always non-NULL so it doesn't need to be > checked. Thus just remove the unnecessary NULL check. Also remove the > unnecessary initializer because the list iterator is always = initialized. >=20 > Signed-off-by: Xiaomeng Tong > --- > drivers/net/wireless/st/cw1200/queue.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) >=20 > diff --git a/drivers/net/wireless/st/cw1200/queue.c = b/drivers/net/wireless/st/cw1200/queue.c > index 12952b1c29df..05392598e273 100644 > --- a/drivers/net/wireless/st/cw1200/queue.c > +++ b/drivers/net/wireless/st/cw1200/queue.c > @@ -90,7 +90,7 @@ static void __cw1200_queue_gc(struct cw1200_queue = *queue, > bool unlock) > { > struct cw1200_queue_stats *stats =3D queue->stats; > - struct cw1200_queue_item *item =3D NULL, *tmp; > + struct cw1200_queue_item *item, *tmp; > bool wakeup_stats =3D false; >=20 > list_for_each_entry_safe(item, tmp, &queue->queue, head) { > @@ -117,7 +117,7 @@ static void __cw1200_queue_gc(struct cw1200_queue = *queue, > queue->overfull =3D false; > if (unlock) > __cw1200_queue_unlock(queue); > - } else if (item) { > + } else { I don't think this is fixing anything here. You are basically just = removing a check that was always true. I'm pretty sure that this check is here to check if either the list is = empty or no element was found. If I'm not wrong, some time ago, lists where not = circular but actually pointed to NULL (or the head was NULL) so this check made sense = but doesn't anymore. The appropriate fix would be only setting 'item' when a break is hit and = keep the original check. > unsigned long tmo =3D item->queue_timestamp + = queue->ttl; > mod_timer(&queue->gc, tmo); > cw1200_pm_stay_awake(&stats->priv->pm_state, > --=20 > 2.17.1 >=20 >=20 I've made those changes already and I'm in the process of upstreaming = them in an organized way, so maybe it would make sense to synchronize, so we don't post = duplicate patches. Jakob=