From owner-freebsd-acpi@FreeBSD.ORG Sun Jul 8 10:28:39 2012 Return-Path: Delivered-To: freebsd-acpi@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EF50F106564A for ; Sun, 8 Jul 2012 10:28:38 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 490A68FC0C for ; Sun, 8 Jul 2012 10:28:38 +0000 (UTC) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id NAA22912; Sun, 08 Jul 2012 13:28:29 +0300 (EEST) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1Snoj7-000GtX-Eu; Sun, 08 Jul 2012 13:28:29 +0300 Message-ID: <4FF960CC.1080909@FreeBSD.org> Date: Sun, 08 Jul 2012 13:28:28 +0300 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:13.0) Gecko/20120620 Thunderbird/13.0.1 MIME-Version: 1.0 To: Taku YAMAMOTO References: <4FF94EC4.1060109@FreeBSD.org> <20120708191937.46148f65.taku@tackymt.homeip.net> In-Reply-To: <20120708191937.46148f65.taku@tackymt.homeip.net> X-Enigmail-Version: 1.4.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "freebsd-acpi@freebsd.org" Subject: Re: disabled CST_CNT write X-BeenThere: freebsd-acpi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: ACPI and power management development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 08 Jul 2012 10:28:39 -0000 on 08/07/2012 13:19 Taku YAMAMOTO said the following: > On Sun, 08 Jul 2012 12:11:32 +0300 > Andriy Gapon wrote: > >> >> acpi_cpu.c has a block of code to write CST_CNT to SMI_CMD, but the block is >> under #ifdef notyet. It seems that the code was added that many years ago and >> never enabled. >> Now, judging from the reports I've seen on this mailing list, it appears that >> _CST changes do happen and the driver seem to handle them sufficiently well. >> I think that a lot of modern platforms do not even provide CST_CNT and assume >> that an OS is able to handle C-state change notifications. >> So, I guess that it should be safe to enable the code in question now. >> >> Could anyone with a FreeBSD laptop and non-zero CST_CNT in FADT please test this? > > My Thinkpad X60 (Core 2 Duo) is such one of them. > Enabling that code makes this laptop correctly raise _CST change > notification on AC status change without a single problem. > Without enabling that, this laptop never generates such notifications. > > In fact, I have been enabling that code locally for more than a couple of > years without a problem :) > > In addition, that does not interfere with jkim's acpi_cx_native2.diff; > I've been enjoying MWAIT C3 with varying sleep depth based upon AC availability. > Thank you very much for the information! I will commit this change. -- Andriy Gapon