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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14967C433FE for ; Sun, 17 Oct 2021 17:17:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E466C60FE3 for ; Sun, 17 Oct 2021 17:17:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344374AbhJQRTn (ORCPT ); Sun, 17 Oct 2021 13:19:43 -0400 Received: from www381.your-server.de ([78.46.137.84]:38046 "EHLO www381.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344366AbhJQRTl (ORCPT ); Sun, 17 Oct 2021 13:19:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=metafoo.de; s=default2002; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID; bh=QBENmn8DWKF/mfK74+vyzNo90m6r1VsVFZ9Mto1R0KI=; b=l8Zu8RB24+vEP3bgA3eSbiG9hh f6kPoPi1rZZ4L/4wbM8+ldImYSDtIckC4t0eisQe4z3f3y6r1rsCmIeTKXHzjcKwdtpXAY/Xf40E2 OY0hKC11YK/OCx69c+6yeqdEhzKRGgVJH2SFdwfGep+voW6jpse0cArwq4X73XyfOaaDe2q0j3ftB AV6h/zSHHeiwUOXN3iobYqpUufBgGuwhViiZVCNDT2Uk7VuFBCPOfHGZAY9w/EXA8JaUXpJgYMt9N 6kkSxft1memtUXT3xzY47SfqUxgp2EdpGOEhPHuPaHdR5rcmjGIUskGuCIW77NI+gtgGWyHfx+RF7 +k6aN9jA==; Received: from sslproxy02.your-server.de ([78.47.166.47]) by www381.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92.3) (envelope-from ) id 1mc9mp-0006tp-9J; Sun, 17 Oct 2021 19:17:27 +0200 Received: from [82.135.83.71] (helo=[192.168.178.20]) by sslproxy02.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mc9mp-000Jj5-3l; Sun, 17 Oct 2021 19:17:27 +0200 Subject: Re: [PATCH v2] iio: accel: sca3000: Use sign_extend32() instead of opencoding sign extension. To: Jonathan Cameron , linux-iio@vger.kernel.org Cc: Jonathan Cameron , Dan Carpenter References: <20211017160303.72441-1-jic23@kernel.org> From: Lars-Peter Clausen Message-ID: <2c475dda-829f-3d7d-da0f-91a4aee1bee8@metafoo.de> Date: Sun, 17 Oct 2021 19:17:26 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <20211017160303.72441-1-jic23@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Authenticated-Sender: lars@metafoo.de X-Virus-Scanned: Clear (ClamAV 0.103.3/26325/Sun Oct 17 10:17:54 2021) Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On 10/17/21 6:03 PM, Jonathan Cameron wrote: > From: Jonathan Cameron > > Whilst nice to get rid of this non obvious code, this also clears a > static checker warning: > > drivers/iio/accel/sca3000.c:734 sca3000_read_raw() > warn: no-op. '((*val) << 19) >> 19' > > Reported-by: Dan Carpenter > Signed-off-by: Jonathan Cameron Reviewed-by: Lars-Peter Clausen --- > v2: > Use the right sign bit (thanks Lars!) > Should be bit 12 for a 13 bit value. > > drivers/iio/accel/sca3000.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/iio/accel/sca3000.c b/drivers/iio/accel/sca3000.c > index cb753a43533c..c6b75308148a 100644 > --- a/drivers/iio/accel/sca3000.c > +++ b/drivers/iio/accel/sca3000.c > @@ -731,8 +731,7 @@ static int sca3000_read_raw(struct iio_dev *indio_dev, > return ret; > } > *val = (be16_to_cpup((__be16 *)st->rx) >> 3) & 0x1FFF; > - *val = ((*val) << (sizeof(*val) * 8 - 13)) >> > - (sizeof(*val) * 8 - 13); > + *val = sign_extend32(*val, 12); > } else { > /* get the temperature when available */ > ret = sca3000_read_data_short(st,