From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751807Ab2DAG3D (ORCPT ); Sun, 1 Apr 2012 02:29:03 -0400 Received: from mga09.intel.com ([134.134.136.24]:49236 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750843Ab2DAG3A (ORCPT ); Sun, 1 Apr 2012 02:29:00 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,352,1309762800"; d="scan'208";a="124127434" Subject: Re: [PATCH] ACPI: evaluate _PS3 when entering D3 Cold From: Lin Ming To: Aaron Lu Cc: Len Brown , "Rafeal J. Wysocki" , linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Zhang Rui , Andiry Xu , Alex He In-Reply-To: <20120401055603.GA11505@localhost.amd.com> References: <1333217910-29579-1-git-send-email-aaron.lu@amd.com> <1333258053.2939.22.camel@minggr> <20120401055603.GA11505@localhost.amd.com> Content-Type: text/plain; charset="UTF-8" Date: Sun, 01 Apr 2012 14:28:57 +0800 Message-ID: <1333261737.2939.84.camel@minggr> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2012-04-01 at 13:56 +0800, Aaron Lu wrote: > Hi, > > On Sun, Apr 01, 2012 at 01:27:33PM +0800, Lin Ming wrote: > > > - if (device->power.states[state].flags.explicit_set) { > > > + /* If state is D3 Cold, try to evaluate _PS3 first */ > > > + if (state == ACPI_STATE_D3_COLD) { > > > + explicit_set = (ps - 1)->flags.explicit_set; > > > + object_name[3] -= 1; > > > + } > > > > I'm not sure whether this works or not. > > > > From ACPI spec, > > > > _PS3 "is used to put the specific device into its D3hot or D3 state" > > > > D3 neither means D3hot nor D3cold. It's an old term before D3hot and > > D3cold were introduced. > I guess D3 has to mean something, right? :-) > > Here is the problem, there is no _PR3 in AMD's implementation, just _PS3. > And since _S0W evaluates 4, I've to put this device into D3 cold state > with _PS3. > > And the ACPI does have some words like: > > ------ > Platform/drivers must assume that the device will have power completely > removed when the device is place into “D3” via _PS3 > ------ > > This is in section 7.2.11: _PR3. > > > > > Another problem: > > > > With your patch, both D3hot and D3cold will evaluate _PS3, right? > > > Yes. > > > Will it have problem on AMD platform if you try to put ODD into D3hot > > state? _PS3 is evaluated, so it actually enters D3Cold state. > > There is no D3 hot support for this device(from the firmware's > perspective), either it is at D0(via _PS0), or it will be at D3 cold(via > _PS3). But this is the generic code. We can't only consider some special device. Maybe we need some flag to tell which D3 state _PS3 is used for. Lin Ming > > > Thanks for the review. > > -Aaron >