From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757375Ab3GVKvW (ORCPT ); Mon, 22 Jul 2013 06:51:22 -0400 Received: from exprod5og116.obsmtp.com ([64.18.0.147]:44360 "EHLO exprod5og116.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753338Ab3GVKvU (ORCPT ); Mon, 22 Jul 2013 06:51:20 -0400 MIME-Version: 1.0 In-Reply-To: <51E9AA6D.3070007@kernel.org> References: <1374162430-30709-1-git-send-email-x0199363@ti.com> <51E816BD.9010302@metafoo.de> <51E9AA6D.3070007@kernel.org> Date: Mon, 22 Jul 2013 13:51:19 +0300 Message-ID: Subject: Re: [PATCH] iio: core: Avoid double minus in sysfs output From: Oleksandr Kravchenko To: Jonathan Cameron Cc: Lars-Peter Clausen , Oleksandr Kravchenko , jic23@cam.ac.uk, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Please ignore this patch for now. I'll rework it soon. It issues warnings when compiling. On Sat, Jul 20, 2013 at 12:06 AM, Jonathan Cameron wrote: > On 07/19/2013 07:15 AM, Oleksandr Kravchenko wrote: >> On Thu, Jul 18, 2013 at 7:24 PM, Lars-Peter Clausen wrote: >>> On 07/18/2013 05:47 PM, Oleksandr Kravchenko wrote: >>>> From: Oleksandr Kravchenko >>>> >>>> This patch fixes the issue with double minus in output when >>>> reading channels from sysfs for IIO_VAL_INT_PLUS_MICRO and >>>> IIO_VAL_INT_PLUS_NANO cases. Until this patch if val and val2 >>>> both are negatives output string contains "--" before >>>> digits. It is result of "-%d..." in sprintf() format. >>>> >>> >>> Hm, this might be a bug in a driver that is triggering this. The idea is >>> that val2 is only allowed to be negative if val is 0. >>> >>> - Lars >>> >> If I calculate val and val2 in next way: >> *val = adc / 1000000; >> *val2 = adc % 1000000; >> both val and val2 could by negative. Do I have to check it in my driver? >> > I guess it is will happen occasionally. In the c89 standard, module for a negative > is implementation specific. Anyone know if we can assume this will work in all cases > within the kernel? -- Oleksandr Kravchenko GlobalLogic P +380633213187 P +380994930248 www.globallogic.com http://www.globallogic.com/email_disclaimer.txt