From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sivaram Nair Subject: Re: [PATCH 2/2] cpuidle: fix sysfs output for power_usage Date: Mon, 17 Dec 2012 10:46:07 +0200 Message-ID: <20121217084607.GN10090@sivaramn-lnx> References: <1355491060-970-1-git-send-email-sivaramn@nvidia.com> <39891276.jhMMUpZpil@vostro.rjw.lan> <20121217073815.GM10090@sivaramn-lnx> <4160971.sv9ruOS3QC@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Received: from hqemgate03.nvidia.com ([216.228.121.140]:3197 "EHLO hqemgate03.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750805Ab2LQIqP (ORCPT ); Mon, 17 Dec 2012 03:46:15 -0500 In-Reply-To: <4160971.sv9ruOS3QC@vostro.rjw.lan> Content-Disposition: inline Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" Cc: "rafael.j.wysocki@intel.com" , "daniel.lezcano@linaro.org" , "shuox.liu@intel.com" , "akpm@linux-foundation.org" , "yanmin_zhang@intel.com" , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" On Mon, Dec 17, 2012 at 08:56:45AM +0100, Rafael J. Wysocki wrote: > On Monday, December 17, 2012 09:38:15 AM Sivaram Nair wrote: > > On Sat, Dec 15, 2012 at 01:03:02AM +0100, Rafael J. Wysocki wrote: > > > On Friday, December 14, 2012 03:17:37 PM Sivaram Nair wrote: > > > > cpuidle_state->power_usage is signed; so change the corresponding sysfs > > > > ops to output signed value instead of unsigned. > > > > > > What's actually wrong with printing it as an unsigned int? > > > > power_usage could have negative values (for example cpuidle/driver.c > > inits this value to -1, -2 etc. when drv->power_specified is not set) and > > these shows up badly in the sysfs output. > > Does "badly" mean "as big positive numbers"? Yes (sorry for not being clearer). > > Should we actually print them at all in those case? Perhaps it'll be better to > make the file appear empty then? May be, but why is power_usage signed in the first place? I also noticed Daniel Lezcano's patches that reduces the scope of this variable. So, perhaps we can just ignore this change. -Sivaram