From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dennis Wassenberg Subject: S0iX Ultra Low Power States Date: Tue, 25 Nov 2014 13:51:37 +0100 Message-ID: <54747B59.2080503@secunet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Return-path: Received: from a.mx.secunet.com ([195.81.216.161]:54562 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750963AbaKYMwD (ORCPT ); Tue, 25 Nov 2014 07:52:03 -0500 Received: from localhost (alg1 [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id DB9F81A0096 for ; Tue, 25 Nov 2014 13:51:53 +0100 (CET) Received: from a.mx.secunet.com ([127.0.0.1]) by localhost (a.mx.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 5l0R95RguYI2 for ; Tue, 25 Nov 2014 13:51:45 +0100 (CET) Received: from mail-essen-01.secunet.de (unknown [10.53.40.204]) by a.mx.secunet.com (Postfix) with ESMTP id 588821A0092 for ; Tue, 25 Nov 2014 13:51:45 +0100 (CET) Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "linux-pm@vger.kernel.org" Hi, I would like to know more about the Linux power management in correlation to the Intel S0iX Ultra Low Power States. Systems which have a Windows 8 Logo must support Connected Standby (or InstantGo, however it is called). One of the requirements getting this logo is that the ACPI firmware must not provide an S3 object in the root of the namespace. This means that Linux can not use the S3 mode. To archive a very low power consumption Microsoft uses the Ultra Low Power States S0i1 and S0i3. Is there a way to use these low power states in linux for Haswell/LynxPoint or Broadwell/Skylake platforms? I read something about these states. Such that they can be activated automatically but there are some preconditions (e.g. certain IO devices have to put into a low power state, graphics off, only one CPU online, ...). If I enter the S1 Low Power State (with additional disable_nonboot_cpus) all of these preconditions should be fulfilled?! But I can not observe that the there is a power consumption less than 1 Watt. Thank you & Best regards, Dennis