From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [PATCH] ACPI: evaluate _PS3 when entering D3 Cold Date: Mon, 9 Apr 2012 01:54:08 +0200 Message-ID: <201204090154.09183.rjw@sisk.pl> References: <1333217910-29579-1-git-send-email-aaron.lu@amd.com> <20120405025609.GA5208@localhost.amd.com> <1333594904.11327.27.camel@minggr> Mime-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from ogre.sisk.pl ([217.79.144.158]:59205 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752425Ab2DHXtl (ORCPT ); Sun, 8 Apr 2012 19:49:41 -0400 In-Reply-To: <1333594904.11327.27.camel@minggr> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Lin Ming Cc: Aaron Lu , Len Brown , linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Zhang Rui , Andiry Xu , Alex He On Thursday, April 05, 2012, Lin Ming wrote: > On Thu, 2012-04-05 at 10:56 +0800, Aaron Lu wrote: > > Hi, > > > > On Thu, Apr 05, 2012 at 10:31:20AM +0800, Lin Ming wrote: > > > > > > > > The only situation where a device can be put into ACPI D3_hot (which is not > > > > the same as PCI D3_hot, mind you) is when: > > > > > > > > (1) There is _PR3 listing some of the device's power resources as "on". > > > > (2) The power resources listed by the _PR3 as "off" are turned off and the > > > > power resources listed by the _PR3 as "on" are left in the "on" state. > > > > > > I don't understand item (2): > > > > > > If the power resource is listed as "off", which means it's already > > > turned off. Then why should it be turned off again? > > > > Rafael, > > I think you misunderstand the meaning of _PR3. > > The _PR3 will evaluate a list of power resources, not two lists(one "on" > > list and one "off" list), as illustrated by Ming below. > > > > And for a device to be put to D3 hot, it should: > > 1 execuate _PS3 first if available > > 2 turn on all the power resources referenced by _PR3 > > 3 turn off all the power resources referenced by previous state But leave the ones listed by _PR3 in the "on" state, you mean? Rafael