From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Lu Subject: Discussion on device's runtime wake capability Date: Tue, 09 Oct 2012 14:23:12 +0800 Message-ID: <5073C2D0.1080900@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mga03.intel.com ([143.182.124.21]:41313 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752443Ab2JIGXR (ORCPT ); Tue, 9 Oct 2012 02:23:17 -0400 Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J. Wysocki" , Len Brown Cc: Huang Ying , Zhang Rui , linux-acpi@vger.kernel.org Hi all, We are using _PRW as a hint to see if a device supports wakeup, this is fine for device which is able to wake the system in a sleep state, but not to wake itself when system is at S0. Moreover, when we are to arm the device runtime wake, I think there is no need to power on the power resources referenced in _PRW, those power resources should be used to give the device ability to wake the system from a sleep state, not to wake itself when system is at S0, so powering thoses power resources on for run wake is a waste. But I may miss something, so it would be very kind of you to point it out if things are not like what I've thought, thanks. BTW, _S0W seems to be a good hint whether the device supports run wake from ACPI's perspective. -Aaron