From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422933AbcFHIeN (ORCPT ); Wed, 8 Jun 2016 04:34:13 -0400 Received: from foss.arm.com ([217.140.101.70]:50939 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161190AbcFHIeK (ORCPT ); Wed, 8 Jun 2016 04:34:10 -0400 Subject: Re: [RFC 1/1] ARM: print MHz in /proc/cpuinfo To: Jon Mason References: <1465333713-14339-1-git-send-email-jon.mason@broadcom.com> <1465333713-14339-2-git-send-email-jon.mason@broadcom.com> Cc: Russell King , Sudeep Holla , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org From: Sudeep Holla Organization: ARM Message-ID: <5757D87E.2080508@arm.com> Date: Wed, 8 Jun 2016 09:34:06 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <1465333713-14339-2-git-send-email-jon.mason@broadcom.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/06/16 22:08, Jon Mason wrote: > Query the CPU core clock in the device tree to determine the core clock > speed. How do guarantee that it's the current frequency of the CPU ? It doesn't even represent the mix or max frequency, so it's incorrect. Some DTs have boot frequency in that entry. > Output this clock rate in /proc/cpuinfo to match the output > from other architectures. The output is intentionally patterned after > the x86 output, to match existing (and possibly expected) convention. > > If any errors are encountered in querying the clock (or the speed is > erroneously zero), nothing will be printed out. Thus any existing > devices that do not have CPU clocks defined in the device tree will > work as before. > What if they just don't have in DT but have DVFS support ? Also whey do we need this support when the user-space can query the CPUFreq sysfs which is more accurate and maintains the current running frequency ? -- Regards, Sudeep