From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754700AbbGXWtw (ORCPT ); Fri, 24 Jul 2015 18:49:52 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:56273 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751824AbbGXWts (ORCPT ); Fri, 24 Jul 2015 18:49:48 -0400 Message-ID: <55B2C105.3040600@roeck-us.net> Date: Fri, 24 Jul 2015 15:49:41 -0700 From: Guenter Roeck User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Pavel Machek CC: Sascha Hauer , linux-pm@vger.kernel.org, Zhang Rui , Eduardo Valentin , linux-kernel@vger.kernel.org, Punit Agrawal , Jean Delvare , Peter Feuerer , Heiko Stuebner , Lukasz Majewski , Stephen Warren , Thierry Reding , linux-acpi@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, linux-samsung-soc@vger.kernel.org, "Rafael J. Wysocki" , Maxime Ripard , Darren Hart , lm-sensors@lm-sensors.org Subject: Re: [PATCH v2] thermal: consistently use int for temperatures References: <1437463292-24844-1-git-send-email-s.hauer@pengutronix.de> <20150723120759.GA17690@amd> <20150724062948.GK18700@pengutronix.de> <55B244BE.1060203@roeck-us.net> <20150724221102.GA31517@amd> In-Reply-To: <20150724221102.GA31517@amd> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=0.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: linux@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/24/2015 03:11 PM, Pavel Machek wrote: > On Fri 2015-07-24 06:59:26, Guenter Roeck wrote: >> On 07/23/2015 11:29 PM, Sascha Hauer wrote: >>> On Thu, Jul 23, 2015 at 02:07:59PM +0200, Pavel Machek wrote: >>>> On Tue 2015-07-21 09:21:32, Sascha Hauer wrote: >>>>> The thermal code uses int, long and unsigned long for temperatures >>>>> in different places. >>>>> >>>>> Using an unsigned type limits the thermal framework to positive >>>>> temperatures without need. Also several drivers currently will report >>>>> temperatures near UINT_MAX for temperatures below 0°C. This will probably >>>>> immediately shut the machine down due to overtemperature if started below >>>>> 0°C. >>>>> >>>>> 'long' is 64bit on several architectures. This is not needed since INT_MAX °mC >>>>> is above the melting point of all known materials. >>>> >>>> Can we do something like >>>> >>>> typedef millicelsius_t int; >>>> >>>> ...to document the units? >>> >>> I am not very fond of typedefs and I am not sure this adds any value. I >>> could change it when more people ask for it, but I just sent the new >>> version without this. >>> >> >> I thought we are supposed to not introduce new typedefs anyway. > > You are not supposed to typedef struct, but typedef for millicelsius_t > would be ok. And it is your only chance if you want people to pay > attention. If you make it int, someone will pass it to long or > something else.. Seems to me that would be just lazyness. The same person might use 'long' even if millicelsius_t is defined. A typedef doesn't preclude people from ignoring it. Guenter