From owner-freebsd-acpi@FreeBSD.ORG Mon Dec 13 20:17:13 2004 Return-Path: Delivered-To: freebsd-acpi@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B533916A4DD for ; Mon, 13 Dec 2004 20:17:13 +0000 (GMT) Received: from www.cryptography.com (li-22.members.linode.com [64.5.53.22]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7499D43D53 for ; Mon, 13 Dec 2004 20:17:13 +0000 (GMT) (envelope-from nate@root.org) Received: from [10.0.0.34] (adsl-67-119-74-222.dsl.sntc01.pacbell.net [67.119.74.222]) by www.cryptography.com (8.12.8/8.12.8) with ESMTP id iBDKHBug001807 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Mon, 13 Dec 2004 12:17:11 -0800 Message-ID: <41BDF8C6.4030607@root.org> Date: Mon, 13 Dec 2004 12:17:10 -0800 From: Nate Lawson User-Agent: Mozilla Thunderbird 0.9 (Windows/20041103) X-Accept-Language: en-us, en MIME-Version: 1.0 To: "M. Warner Losh" References: <20041213190604.GA81993@svm.csie.ntu.edu.tw> <20041213.121233.104111469.imp@harmony.village.org> <41BDF6A7.3040702@root.org> <20041213.131052.42773193.imp@bsdimp.com> In-Reply-To: <20041213.131052.42773193.imp@bsdimp.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit cc: acpi@FreeBSD.ORG cc: rafan@infor.org Subject: Re: current powerstate and manually turn on/off? X-BeenThere: freebsd-acpi@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: ACPI and power management development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Dec 2004 20:17:13 -0000 M. Warner Losh wrote: > In message: <41BDF6A7.3040702@root.org> > Nate Lawson writes: > : Warner Losh wrote: > : >>By using sysctl, I do know what's the current powerstate > : >>of each device. I wounder is there any command or sysctl > : >>that can manually turn device on or off? > : > > : > > : > Not really, no. > : > : I think this is something the drivers should handle and we don't need to > : add user access to power states since it's probably the biggest way to > : shoot yourself in the foot. We already power down devices with no > : driver attached and once drivers get smart about powering down devices > : that are idle, this would cover all scenarios. > > It would be nice to have a way to say "This is a really strong hint > that you are now idle, go to lowest power, highest latency to get out > of it mode." I believe the driver itself has best knowledge of this, based on refcount, recent I/O, etc. You don't want the user turning off things without the driver's knowledge. -- Nate