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 265D9C433F5 for ; Sun, 17 Oct 2021 17:32:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0698060FE3 for ; Sun, 17 Oct 2021 17:32:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344422AbhJQRfD (ORCPT ); Sun, 17 Oct 2021 13:35:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:59034 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344366AbhJQRfC (ORCPT ); Sun, 17 Oct 2021 13:35:02 -0400 Received: from jic23-huawei (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B98E460FDC; Sun, 17 Oct 2021 17:32:51 +0000 (UTC) Date: Sun, 17 Oct 2021 18:37:05 +0100 From: Jonathan Cameron To: Lars-Peter Clausen Cc: linux-iio@vger.kernel.org, Jonathan Cameron , Dan Carpenter Subject: Re: [PATCH v2] iio: accel: sca3000: Use sign_extend32() instead of opencoding sign extension. Message-ID: <20211017183705.472210ba@jic23-huawei> In-Reply-To: <2c475dda-829f-3d7d-da0f-91a4aee1bee8@metafoo.de> References: <20211017160303.72441-1-jic23@kernel.org> <2c475dda-829f-3d7d-da0f-91a4aee1bee8@metafoo.de> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Sun, 17 Oct 2021 19:17:26 +0200 Lars-Peter Clausen wrote: > 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 to your tag and applied. Thanks Jonathan > > > --- > > 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, > >