From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751438AbaCFFWs (ORCPT ); Thu, 6 Mar 2014 00:22:48 -0500 Received: from mga01.intel.com ([192.55.52.88]:63942 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750827AbaCFFWr (ORCPT ); Thu, 6 Mar 2014 00:22:47 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,598,1389772800"; d="scan'208";a="486958153" Message-ID: <531805D4.6040806@linux.intel.com> Date: Thu, 06 Mar 2014 13:21:24 +0800 From: "Li, Aubrey" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: "H. Peter Anvin" , Matthew Garrett , mingo@redhat.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, "alan@linux.intel.com" Subject: Re: [PATCH] x86: new Intel Atom SoC power management controller driver References: <5317EC0C.4010807@linux.intel.com> <5317F044.8080407@linux.intel.com> In-Reply-To: <5317F044.8080407@linux.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014/3/6 11:49, H. Peter Anvin wrote: > On 03/05/2014 07:31 PM, Li, Aubrey wrote: >> The Power Management Controller (PMC) controls many of the power >> management features present in the SoC. This driver provides >> interface to configure the Power Management Controller (PMC). >> >> This driver exposes PMC device state and sleep state residency >> via debugfs for observation: >> /sys/kernel/debugfs/pmc_atom/dev_state >> /sys/kernel/debugfs/pmc_atom/sleep_state >> >> This driver also provides a native power off function via PMC PCI >> IO port. >> > > What is the reason for putting this in debugfs? S0ix support on Atom SoC needs all of the devices under south complex to be quiesced, as well as the devices under north complex. This interface shows all of the devices states under platform control unit. If the system is not able to enter S0ix, we have a way to diagnose. Or if the system entered S0ix, we have counters to show S0ix entered and its residency. Thanks, -Aubrey > > -hpa > > > >