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=-11.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=unavailable 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 D8B91C433E1 for ; Sat, 22 Aug 2020 10:58:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3AEE2067C for ; Sat, 22 Aug 2020 10:58:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598093880; bh=BqxYd2pOokGPeK4LyapSM4x47jhdQWKuct76BNr8mIQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=Cx+aaCUzLj0mKQTc3QsAciCF+flzc+EvzE9W6oAKI1m9lTbXU9Dufqar3sqopopS8 sSifOqJOGvsndYszjol6Mh3x0JnSy3R0SpqoSvW8FDUUdz69rTUHdKKqfdNnMxT569 EqY5YGQWpxIY3IyjAkAfN8yutf1XCuZP2GeTCVP4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727919AbgHVK57 (ORCPT ); Sat, 22 Aug 2020 06:57:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:36318 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727877AbgHVK5C (ORCPT ); Sat, 22 Aug 2020 06:57:02 -0400 Received: from archlinux (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (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 F13392067C; Sat, 22 Aug 2020 10:56:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598093821; bh=BqxYd2pOokGPeK4LyapSM4x47jhdQWKuct76BNr8mIQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=KCE5cT2m3bt54RR8mfuyBOBzCYm9tlrUYymZbKgaCgKyPLtp3qhH4mZZFff1Xp61x QhGBRFCkeZLTy4UX/i+UuuzVGrrNuHKgo+lDWgxu2PJitsVvrp2EwmmU/c7Jlli82s zN9hWOcmruSVKMoE9P/3uGRmEsa++M2UnqAykypk= Date: Sat, 22 Aug 2020 11:56:54 +0100 From: Jonathan Cameron To: Anand Ashok Dumbre Cc: knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, michal.simek@xilinx.com, git@xilinx.com, linux-iio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, anandash@xilinx.com Subject: Re: [PATCH] iio: Fixed IIO_VAL_FRACTIONAL calcuation for negative values Message-ID: <20200822115654.0d7f716f@archlinux> In-Reply-To: <1597946984-25844-1-git-send-email-anand.ashok.dumbre@xilinx.com> References: <1597946984-25844-1-git-send-email-anand.ashok.dumbre@xilinx.com> X-Mailer: Claws Mail 3.17.6 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 20 Aug 2020 11:09:44 -0700 Anand Ashok Dumbre wrote: > This patch fixes IIO_VAL_FRACTIONAL calculation for negative > values where the exponent is 0. > > Signed-off-by: Anand Ashok Dumbre Hi, I would thrown in an example for this description. Also useful to know if there is a existing driver that is broken and hence we need to backport this. If that is the case, please try to figure out an appropriate fixes tag. Comments inline + the email footer issue needs sorting out. Thanks, Jonathan > --- > drivers/iio/industrialio-core.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c > index f72c2dc..cd43b17 100644 > --- a/drivers/iio/industrialio-core.c > +++ b/drivers/iio/industrialio-core.c > @@ -554,6 +554,7 @@ static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type, > { > unsigned long long tmp; > int tmp0, tmp1; > + s64 tmp2; > bool scale_db = false; > > switch (type) { > @@ -576,10 +577,13 @@ static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type, > else > return snprintf(buf, len, "%d.%09u", vals[0], vals[1]); > case IIO_VAL_FRACTIONAL: > - tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]); > + tmp2 = div_s64((s64)vals[0] * 1000000000LL, vals[1]); > tmp1 = vals[1]; > - tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1); > - return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1)); > + tmp0 = (int)div_s64_rem(tmp2, 1000000000, &tmp1); > + if ((tmp2 < 0) && (tmp0 == 0)) > + return snprintf(buf, len, "-%d.%09u", tmp0, abs(tmp1)); Given tmp0 == 0, this might be clearer as return snprintf(buf, len, "-0.%09u", abs(tmp1)); > + else > + return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1)); > case IIO_VAL_FRACTIONAL_LOG2: > tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]); > tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1); > -- > 2.7.4 > > This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately. As Andy said, this footer is a problem...