From owner-freebsd-acpi@FreeBSD.ORG Mon Dec 13 20:27:36 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 DBAC416A4CE for ; Mon, 13 Dec 2004 20:27:36 +0000 (GMT) Received: from harmony.village.org (rover.village.org [168.103.84.182]) by mx1.FreeBSD.org (Postfix) with ESMTP id B854443D2F for ; Mon, 13 Dec 2004 20:27:35 +0000 (GMT) (envelope-from imp@bsdimp.com) Received: from localhost (warner@rover2.village.org [10.0.0.1]) by harmony.village.org (8.13.1/8.13.1) with ESMTP id iBDKOex6082575; Mon, 13 Dec 2004 13:24:40 -0700 (MST) (envelope-from imp@bsdimp.com) Date: Mon, 13 Dec 2004 13:24:39 -0700 (MST) Message-Id: <20041213.132439.41632908.imp@bsdimp.com> To: nate@root.org From: "M. Warner Losh" In-Reply-To: <41BDF8C6.4030607@root.org> References: <41BDF6A7.3040702@root.org> <20041213.131052.42773193.imp@bsdimp.com> <41BDF8C6.4030607@root.org> X-Mailer: Mew version 3.3 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii 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 20:27:37 -0000 CYIn message: <41BDF8C6.4030607@root.org> Nate Lawson writes: : 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. I agree. That's why I said 'strong hint' rather than 'command'. Warner