Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751823AbaBZFPf (ORCPT ); Wed, 26 Feb 2014 00:15:35 -0500 Received: from mail-ob0-f181.google.com ([209.85.214.181]:49002 "EHLO mail-ob0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751067AbaBZFPc (ORCPT ); Wed, 26 Feb 2014 00:15:32 -0500 MIME-Version: 1.0 In-Reply-To: <1456811.7asrQYHEt1@vostro.rjw.lan> References: <15ccc0609cb9ee3db0ad3a95b29bf69d11ea197c.1392375504.git.viresh.kumar@linaro.org> <3894986.dK3STNSG71@vostro.rjw.lan> <1456811.7asrQYHEt1@vostro.rjw.lan> Date: Wed, 26 Feb 2014 10:45:32 +0530 Message-ID: Subject: Re: [PATCH 1/2] cpufreq: Return error if ->get() failed in cpufreq_update_policy() From: Viresh Kumar To: "Rafael J. Wysocki" Cc: "Srivatsa S. Bhat" , Lists linaro-kernel , "cpufreq@vger.kernel.org" , "linux-pm@vger.kernel.org" , Linux Kernel Mailing List , Pierre Ossman 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 On 26 February 2014 03:59, Rafael J. Wysocki wrote: > Yes, what exactly do we need it for in the core? Its probably there to make things faster. We cache the value so that we don't go to the hardware to read/calculate that again. Isn't it? And we need to know current freq on many occasions. One of that is that many drivers need to know the relation between current and new freq before they can make the change. As they might need to play with volt regulators before or after the freq change. Also it is used mainly in our loops_per_jiffiy calculations. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/