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 X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E36DFC3A5A0 for ; Mon, 20 Apr 2020 12:13:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C06B7206D6 for ; Mon, 20 Apr 2020 12:13:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="Z59B/qFc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726911AbgDTMNa (ORCPT ); Mon, 20 Apr 2020 08:13:30 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:36580 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726402AbgDTMNZ (ORCPT ); Mon, 20 Apr 2020 08:13:25 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 03KBqb1C187946; Mon, 20 Apr 2020 12:13:16 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=C7+fcI4KZiXfIWW4U2ZyjNo5atQa1VYMh+jlIP/eLqg=; b=Z59B/qFcgrXjwvapB0YXbiA1Yn0eCWArZonLrcdXNPnDLJa4sqvAVyR2SbBaH1kGvhYk zwbnoQik+OQRLeMkkIe3SEN/kOyPZ20qakX+GJwVD7ijsa9XhYQFdjKECQVPr3/yoVWu 51CF0obZjwaJqyqmNbi1yAKIlCW7+0LH7cZjMhacR8s2H3wSBXZguHdmhO5yo3Yml63f 6NAZtVI7Xe5EJpDzxwOn5hU66Kp/KaLQRVp22BLvw/P4PZol1Yv01X1pmZJsy2gndTJ1 IW+QqlTWpD5rPvaff3Qiz2T1bxO6IFZsXdS6VpFgN+U6UBjXZjgjVUKpRzO0Pmu60KWW Sg== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 30ft6mxrnh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 20 Apr 2020 12:13:16 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 03KC8Io9102341; Mon, 20 Apr 2020 12:11:15 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3030.oracle.com with ESMTP id 30gb1d2r19-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 20 Apr 2020 12:11:15 +0000 Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 03KCB9nC001397; Mon, 20 Apr 2020 12:11:12 GMT Received: from kadam (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 20 Apr 2020 05:11:09 -0700 Date: Mon, 20 Apr 2020 15:10:59 +0300 From: Dan Carpenter To: Oscar Carter Cc: Forest Bond , Greg Kroah-Hartman , devel@driverdev.osuosl.org, Malcolm Priestley , "John B . Wyatt IV" , linux-kernel@vger.kernel.org, Colin Ian King Subject: Re: [PATCH] staging: vt6656: Use fls instead of for loop in vnt_update_top_rates Message-ID: <20200420121059.GC2659@kadam> References: <20200419100921.5421-1-oscar.carter@gmx.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200419100921.5421-1-oscar.carter@gmx.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9596 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 suspectscore=0 spamscore=0 mlxlogscore=849 mlxscore=0 malwarescore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004200107 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9596 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 bulkscore=0 priorityscore=1501 impostorscore=0 adultscore=0 phishscore=0 lowpriorityscore=0 malwarescore=0 clxscore=1015 mlxlogscore=914 mlxscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004200107 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 19, 2020 at 12:09:21PM +0200, Oscar Carter wrote: > - for (i = RATE_11M;; i--) { > - if (priv->basic_rates & (u16)(1 << i)) { > - top_cck = i; > - break; > - } > - if (i == RATE_1M) > - break; > - } > + pos = fls(priv->basic_rates & GENMASK(RATE_54M, RATE_6M)); > + priv->top_ofdm_basic_rate = pos ? pos-- : RATE_24M; ^^^^^ Argh... Come on. I don't want to have to break out the C standard to see if this is defined behavior and where the sequence points are. A pre-op would be clear but the most clear thing is to write it like this: priv->top_ofdm_basic_rate = pos ? (pos - 1) : RATE_24M; > > - priv->top_cck_basic_rate = top_cck; > + pos = fls(priv->basic_rates & GENMASK(RATE_11M, RATE_1M)); > + priv->top_cck_basic_rate = pos ? pos-- : RATE_1M; ^^^^^ Same. regards, dan carpenter