From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753360Ab3KYLzG (ORCPT ); Mon, 25 Nov 2013 06:55:06 -0500 Received: from mga02.intel.com ([134.134.136.20]:2694 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751994Ab3KYLzD (ORCPT ); Mon, 25 Nov 2013 06:55:03 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,767,1378882800"; d="scan'208";a="414199645" Message-ID: <52933AB5.9060409@intel.com> Date: Mon, 25 Nov 2013 19:55:33 +0800 From: Lan Tianyu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130612 Thunderbird/17.0.6 MIME-Version: 1.0 To: "Rafael J. Wysocki" CC: Viresh Kumar , hg197@gmx.de, "cpufreq@vger.kernel.org" , "linux-pm@vger.kernel.org" , Linux Kernel Mailing List Subject: Re: [PATCH] Cpufreq: Change sysfs interface cpuinfo_cur_freq access privilege References: <1385348018-30525-1-git-send-email-tianyu.lan@intel.com> <5292E133.1040800@intel.com> <5074010.ha99UACE9S@vostro.rjw.lan> In-Reply-To: <5074010.ha99UACE9S@vostro.rjw.lan> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/25/2013 07:26 PM, Rafael J. Wysocki wrote: > On Monday, November 25, 2013 01:33:39 PM Lan Tianyu wrote: >> On 2013年11月25日 12:30, Viresh Kumar wrote: >>> On 25 November 2013 08:23, Lan Tianyu wrote: >>>> Currently, cpuinfo_cur_freq is only accessible for root user while >>>> other cpufreq sysfs interfaces(E,G scaling_cur_freq) are available >>>> to ordinary user. This seems make no sense. This patch is to change >>>> it. >>> >>> There is nothing wrong with the code and so this is more of a design >>> change.. >>> >>> Probably Rafael can help us here as cpufreq_cur_freq will read stuff >>> directly from hardware instead of using cached value in software. >> >> I think so, too. I also tried to checking the reason of the privilege by >> git log but the code was there before linux kernel being migrated to git >> repository. > > And it has always behaved in the same way? Then I wouldn't change it. > It has been there since 2.6.12-rc2 or more early. But the cpuinfo_cur_freq is read-only and seems no harmful. Request from bug 65611. https://bugzilla.kernel.org/show_bug.cgi?id=65611. > Thanks! > -- Best Regards Tianyu Lan