From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261527AbVGGPZy (ORCPT ); Thu, 7 Jul 2005 11:25:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261502AbVGGPX6 (ORCPT ); Thu, 7 Jul 2005 11:23:58 -0400 Received: from smtp103.rog.mail.re2.yahoo.com ([206.190.36.81]:56720 "HELO smtp103.rog.mail.re2.yahoo.com") by vger.kernel.org with SMTP id S261429AbVGGPGQ (ORCPT ); Thu, 7 Jul 2005 11:06:16 -0400 From: Shawn Starr Organization: sh0n.net To: hdaps-devel@lists.sourceforge.net Subject: Re: [Hdaps-devel] Re: Head parking (was: IBM HDAPS things are looking up) Date: Thu, 7 Jul 2005 11:06:10 -0400 User-Agent: KMail/1.8.1 Cc: Jens Axboe , Lenz Grimmer , Arjan van de Ven , Alejandro Bonilla , Jesper Juhl , Dave Hansen , LKML List References: <42C8C978.4030409@linuxwireless.org> <42CCEAA7.1010807@grimmer.com> <20050707084825.GG1823@suse.de> In-Reply-To: <20050707084825.GG1823@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200507071106.10946.shawn.starr@rogers.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Model: HTS548080M9AT00 (Hitachi) Laptop: T42. segfault:/home/spstarr# ./a /dev/hda head parked Seems to park, heard it click :) Shawn. On July 7, 2005 04:48, Jens Axboe wrote: > On Thu, Jul 07 2005, Lenz Grimmer wrote: > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > Hi, > > > > Jens Axboe wrote: > > > ATA7 defines a park maneuvre, I don't know how well supported it is > > > yet though. You can test with this little app, if it says 'head > > > parked' it works. If not, it has just idled the drive. > > > > Great! Thanks for digging this up - it works on my T42, using a Fujitsu > > MHT2080AH drive: > > > > lenz@metis:~/work/ibm_hdaps> sudo ./headpark /dev/hda > > head parked > > > > Judging from the sound the drive makes, this is the same operation that > > the windows tool performs. > > Very cool, I wasn't sure if this was a 'new' feature waiting to be > implemented in drives or if ata7 just documented existing use in some > drives. > > How long did the park take? Spec states it can take up to 500ms. > > > However, the head does not remain parked for a very long time, > > especially if there is a lot of disk activity going on (I tested it by > > running a "find /" in parallel). The head parks, but leaves the park > > position immediately afterwards again. I guess now we need to find a way > > to "nail" the head into the parking position for some time - otherwise > > it may already be on its way back to the platter before the laptop hits > > the ground... > > The head just remains parked until the next command is issued. This > needs to be combined with some ide help, to freeze the queue. Perhaps > some sysfs file so you could do > > # echo park > /sys/block/hda/device/head_state > > Or whatever, at least just exposing this possibility so that the drive > internally can block future io until a 'resume' command is issued.