From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261256AbVFYULr (ORCPT ); Sat, 25 Jun 2005 16:11:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261327AbVFYULq (ORCPT ); Sat, 25 Jun 2005 16:11:46 -0400 Received: from twilight.ucw.cz ([81.30.235.3]:22943 "EHLO suse.cz") by vger.kernel.org with ESMTP id S261256AbVFYUJl (ORCPT ); Sat, 25 Jun 2005 16:09:41 -0400 Date: Sat, 25 Jun 2005 22:09:53 +0200 From: Vojtech Pavlik To: Alejandro Bonilla Cc: Pavel Machek , Paul Sladen , linux-thinkpad@linux-thinkpad.org, Eric Piel , borislav@users.sourceforge.net, "'Yani Ioannou'" , linux-kernel@vger.kernel.org, hdaps-devel@lists.sourceforge.net Subject: Re: [ltp] IBM HDAPS Someone interested? (Accelerometer) Message-ID: <20050625200953.GA1591@ucw.cz> References: <1119559367.20628.5.camel@mindpipe> <20050625144736.GB7496@atrey.karlin.mff.cuni.cz> <42BD9EBD.8040203@linuxwireless.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <42BD9EBD.8040203@linuxwireless.org> User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jun 25, 2005 at 01:13:17PM -0500, Alejandro Bonilla wrote: > I have a question here, how do you guys think that the head is parked, > is it done by the controller directly, which then sends the command to > the HD to park the head, or this is done by the operating system in some > kind of way? > > I think the OS or user space is too slow like to react to send a park > command to the hard drive, so this most be done directly by the embedded > controller, but still I think it needs some input from the OS, to > initialize it's settings. The only way to park a drive is to send a command to it through the IDE interface. This can't be done by the controller itself, since the controller in the ThinkPad is a classic Intel ICH chip which only passes commands around. The OS is definitely fast enough for this kind of task, it's doable even in userspace, although not easy. > i.e. after all, in windows you do have the settings in the software > for HDAPS, but it looks like it is _not_ managed by the operating > system at all if there is some type of action to be taken. This is > also probably why HDAPS won't kick in until booted, and that is > because it needs to load its config setup by the software. > This is what I think, please correct me if I'm saying something crazy. It is definitely all done by the windows kernel driver. -- Vojtech Pavlik SuSE Labs, SuSE CR