From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Lu Subject: Re: Discussion on device's runtime wake capability Date: Tue, 9 Oct 2012 22:44:10 +0800 Message-ID: <20121009144407.GA1426@localhost.localdomain> References: <5073C2D0.1080900@intel.com> <744357E9AAD1214791ACBA4B0B90926322FF88@SHSMSX101.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pb0-f46.google.com ([209.85.160.46]:49346 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753329Ab2JIOoS (ORCPT ); Tue, 9 Oct 2012 10:44:18 -0400 Received: by mail-pb0-f46.google.com with SMTP id rr4so5256279pbb.19 for ; Tue, 09 Oct 2012 07:44:17 -0700 (PDT) Content-Disposition: inline In-Reply-To: <744357E9AAD1214791ACBA4B0B90926322FF88@SHSMSX101.ccr.corp.intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Zhang, Rui" Cc: "Rafael J. Wysocki" , Len Brown , "Huang, Ying" , "linux-acpi@vger.kernel.org" On Tue, Oct 09, 2012 at 06:39:08AM +0000, Zhang, Rui wrote: > > > > -----Original Message----- > > From: linux-acpi-owner@vger.kernel.org [mailto:linux-acpi- > > owner@vger.kernel.org] On Behalf Of Aaron Lu > > Sent: Tuesday, October 09, 2012 2:23 PM > > To: Rafael J. Wysocki; Len Brown > > Cc: Huang, Ying; Zhang, Rui; linux-acpi@vger.kernel.org > > Subject: Discussion on device's runtime wake capability > > Importance: High > > > > 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. > > > Sounds reasonable to me. > To do runtime wake, we only need to power on the resources in _PR0. That would keep the device in D0 state :-) We can put the device into a lower power state which _S0W permits for run wake. -Aaron > > > 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. > > > Agreed. > > > > -Aaron > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" > > in the body of a message to majordomo@vger.kernel.org More majordomo > > info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html