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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham 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 D7C86C43331 for ; Sat, 9 Nov 2019 11:55:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E52A2196F for ; Sat, 9 Nov 2019 11:55:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573300525; bh=z1soBy9NAqy5/dz3HxjryiA+YZGAJ0h1B0pagTmu464=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=rlhzY6iVh0TWmMR0hE6ObwvM7Hwidq4xLXB++CG9ae7EiXHwFh1QBNO0b6xVIHirq 4WSDEhInADYSw3La+ndbes5NP54nOup7Tg8yyTHrKhIRhYpGqmseTTGv8+1XRrv0DS xX9gASzLkYftLpi4UHx2DDxoepruCzm88vYmVVmA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726282AbfKILzZ (ORCPT ); Sat, 9 Nov 2019 06:55:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:60186 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726252AbfKILzZ (ORCPT ); Sat, 9 Nov 2019 06:55:25 -0500 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 1A4C5207FF; Sat, 9 Nov 2019 11:55:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573300524; bh=z1soBy9NAqy5/dz3HxjryiA+YZGAJ0h1B0pagTmu464=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=uhhq63ibHSgSl5sZkm+gJvHyv1VcRofdyHSqUTdn24ZNAAgQODeVpS/TeJENLcRAl UtjcoLZZ8ZWgnCn8u2ZJcCvwM8GpjIL0cOHsIHVU2XMXEPIfvm2KDQpHYFwYbBQJqj L7Vf81LSVn+HFxcNaNMgTJPWgzWkyjPARSjxJVnE= Date: Sat, 9 Nov 2019 11:55:19 +0000 From: Jonathan Cameron To: Alexander Stein 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 Message-ID: <20191109115519.14ba0bdc@archlinux> In-Reply-To: <4116142.9TFg0imz4M@ws-140106> References: <20190822060607.25339-1-alexander.stein@systec-electronic.com> <4116142.9TFg0imz4M@ws-140106> X-Mailer: Claws Mail 3.17.4 (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-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Thu, 07 Nov 2019 14:54:52 +0100 Alexander Stein wrote: > 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 Apologies. I'd missed this v2 entirely for some reason. It looks correct to me, but as Lars had inputs on v1... Lars, could you take a quick look at this v2 and give an ack if you are happy with it. Thanks, Jonathan > > --- > > 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; > > > >