From owner-freebsd-acpi@FreeBSD.ORG Sun Jul 8 10:19:42 2012 Return-Path: Delivered-To: freebsd-acpi@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 0C5C51065676; Sun, 8 Jul 2012 10:19:42 +0000 (UTC) (envelope-from taku@tackymt.homeip.net) Received: from basalt.tackymt.homeip.net (unknown [IPv6:2001:3e0:577:0:20d:61ff:fecc:2253]) by mx1.freebsd.org (Postfix) with ESMTP id 9B7228FC14; Sun, 8 Jul 2012 10:19:41 +0000 (UTC) Received: from basalt.tackymt.homeip.net (localhost [127.0.0.1]) by basalt.tackymt.homeip.net (Postfix) with ESMTP id 791CF83A0; Sun, 8 Jul 2012 19:19:40 +0900 (JST) X-Virus-Scanned: amavisd-new at tackymt.homeip.net Received: from localhost by basalt.tackymt.homeip.net (amavisd-new, unix socket) with ESMTP id g0GXqs3N7Qd2; Sun, 8 Jul 2012 19:19:37 +0900 (JST) Received: from basalt.tackymt.homeip.net (basalt.tackymt.homeip.net [IPv6:2001:3e0:577:0:20d:61ff:fecc:2253]) by basalt.tackymt.homeip.net (Postfix) with ESMTPSA; Sun, 8 Jul 2012 19:19:37 +0900 (JST) Date: Sun, 8 Jul 2012 19:19:37 +0900 From: Taku YAMAMOTO To: Andriy Gapon Message-Id: <20120708191937.46148f65.taku@tackymt.homeip.net> In-Reply-To: <4FF94EC4.1060109@FreeBSD.org> References: <4FF94EC4.1060109@FreeBSD.org> X-Mailer: Sylpheed 3.0.3 (GTK+ 2.24.6; i386-portbld-freebsd9.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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 10:19:42 -0000 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. -- -|-__ YAMAMOTO, Taku | __ < - A chicken is an egg's way of producing more eggs. -