From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261569AbVGDH1i (ORCPT ); Mon, 4 Jul 2005 03:27:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261554AbVGDH1g (ORCPT ); Mon, 4 Jul 2005 03:27:36 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:57051 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S261591AbVGDHVO (ORCPT ); Mon, 4 Jul 2005 03:21:14 -0400 Date: Mon, 4 Jul 2005 09:22:31 +0200 From: Jens Axboe To: Arjan van de Ven Cc: Alejandro Bonilla , Lenz Grimmer , Jesper Juhl , Dave Hansen , Henrik Brix Andersen , hdaps-devel@lists.sourceforge.net, LKML List Subject: Re: IBM HDAPS things are looking up (was: Re: [Hdaps-devel] Re: [ltp] IBM HDAPS Someone interested? (Accelerometer)) Message-ID: <20050704072231.GG1444@suse.de> References: <9a8748490507031832546f383a@mail.gmail.com> <42C8D06C.2020608@grimmer.com> <20050704061713.GA1444@suse.de> <42C8C978.4030409@linuxwireless.org> <20050704063741.GC1444@suse.de> <1120461401.3174.10.camel@laptopd505.fenrus.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1120461401.3174.10.camel@laptopd505.fenrus.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 04 2005, Arjan van de Ven wrote: > > > > This is exactly what I said. Use hdparm to make the HD park > > > inmediatelly. I did send the email to the HDPARM developer, but he never > > > replied. I asked him what would be the best way to make the HD park with > > > no exception and then let it come back 5 or 10 seconds later. > > > > IIRC, you don't have to do anything to wake up the drive after a > > STANDBYNOW command, if you want to be on the safe side you just issue an > > IDLEIMMEDIATE. So your code will look something like: > > the problem for this will be that this app will also want to prevent ANY > io going to the disk for a few seconds. > > I mean, what use is parking the head if you notice the laptop falling, > when the kernel submits IO to it and wakes it up again before it hits > the ground :) Yeah, that likely needs a little help from the ide driver. If you force a spindown, you will effectively have parked the head for as long as the spindown + spinup takes. That could turn out to be enough, it will take more than 1-2 seconds anyways. -- Jens Axboe