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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 88A56C5DF61 for ; Thu, 7 Nov 2019 14:03:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 66D0A214D8 for ; Thu, 7 Nov 2019 14:03:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730985AbfKGODa convert rfc822-to-8bit (ORCPT ); Thu, 7 Nov 2019 09:03:30 -0500 Received: from ox4u.de ([212.118.221.216]:54322 "EHLO s1.ox4u.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726754AbfKGODa (ORCPT ); Thu, 7 Nov 2019 09:03:30 -0500 X-Greylist: delayed 514 seconds by postgrey-1.27 at vger.kernel.org; Thu, 07 Nov 2019 09:03:29 EST Received: by s1.ox4u.de (Postfix, from userid 65534) id D9EFB26012A; Thu, 7 Nov 2019 14:54:53 +0100 (CET) Received: from ws-140106.localnet (unknown [212.185.67.146]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by s1.ox4u.de (Postfix) with ESMTPSA id 0A753260113; Thu, 7 Nov 2019 14:54:52 +0100 (CET) From: Alexander Stein To: Jonathan Cameron Cc: Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/1] iio: core: Fix fractional format generation Date: Thu, 07 Nov 2019 14:54:52 +0100 Message-ID: <4116142.9TFg0imz4M@ws-140106> In-Reply-To: <20190822060607.25339-1-alexander.stein@systec-electronic.com> References: <20190822060607.25339-1-alexander.stein@systec-electronic.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="iso-8859-1" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Gentle ping On Thursday, August 22, 2019, 8:06:07 AM CET Alexander Stein wrote: > In case the result is -0.3252 tmp0 is 0 after the div_s64_rem, so tmp0 is > non-negative which results in an output of 0.3252. > Fix this by explicitly handling the negative sign ourselves. > > Signed-off-by: Alexander Stein > --- > Changes in v2: > * Support vals[0] >= and vals[1] < 0 in IIO_VAL_FRACTIONAL > * Note: IIO_VAL_FRACTIONAL is untested, as I lack hardware > * Note2: Currently IIO_VAL_FRACTIONAL is only called with vals[1] from > in-kernel drivers AFAICS > > drivers/iio/industrialio-core.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c > index 245b5844028d..247338142c87 100644 > --- a/drivers/iio/industrialio-core.c > +++ b/drivers/iio/industrialio-core.c > @@ -568,6 +568,7 @@ static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type, > { > unsigned long long tmp; > int tmp0, tmp1; > + char *sign; > bool scale_db = false; > > switch (type) { > @@ -593,11 +594,17 @@ static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type, > tmp = 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)); > + if (vals[1] < 0) { > + sign = vals[0] >= 0 ? "-" : ""; > + } else { > + sign = vals[0] < 0 ? "-" : ""; > + } > + return snprintf(buf, len, "%s%u.%09u", sign, abs(tmp0), abs(tmp1)); > case IIO_VAL_FRACTIONAL_LOG2: > + sign = vals[0] < 0 ? "-" : ""; > tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]); > tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1); > - return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1)); > + return snprintf(buf, len, "%s%u.%09u", sign, abs(tmp0), abs(tmp1)); > case IIO_VAL_INT_MULTIPLE: > { > int i; > -- Dipl-Inf. Alexander Stein SYS TEC electronic AG Am Windrad 2 08468 Heinsdorfergrund Germany Tel: +49-3765-38600-0, Fax: +49-3765-38600-4100 Email : alexander.stein@systec-electronic.com Internet: http://www.systec-electronic.com Board of Directors: Dipl.-Ing. Ronald Sieber, Dipl.-Ing. Dirk Bause Chairman of the Supervisory Board: Dipl.-Phys. Siegmar Schmidt Commercial registry: Amtsgericht Chemnitz, HRB 32220; USt.-Id Nr. 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