From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kristen Carlson Accardi Subject: Re: [PATCH] ata: ahci: power off unused ports Date: Tue, 27 May 2008 16:32:51 -0700 Message-ID: <20080527163251.04054a74@appleyard> References: <20080508161008.59361de5@appleyard> <20080527030854.GC7515@mit.edu> <20080527143202.4bab5bf0@appleyard> <20080527225926.GE6843@mit.edu> Reply-To: kristen.c.accardi@intel.com Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from mga01.intel.com ([192.55.52.88]:53353 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754160AbYE0Xlx (ORCPT ); Tue, 27 May 2008 19:41:53 -0400 In-Reply-To: <20080527225926.GE6843@mit.edu> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Theodore Tso Cc: jeff@garzik.org, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org On Tue, 27 May 2008 18:59:26 -0400 Theodore Tso wrote: > On Tue, May 27, 2008 at 02:32:02PM -0700, Kristen Carlson Accardi wrote: > > > > As far as I know the patch has gone nowhere. I believe that > > Jeff wanted something more flexible than the module parameter that > > I provided to override the BIOS options. I am not working on this, > > I figured he had a pretty firm idea what he wanted so he was better > > equipped to write the patch. > > Thanks Kristen, > > Can you say which laptops you had tested this on where it saved power? > (Did you test any Thinkpads, in particular?) I'm wondering if it's > worth trying to forward port your patch as a private mod to my kernel; > 30 to 40 minutes of extra battery life is nothing to sneeze at! > > - Ted > I tested this on an Intel mobile software development platform with a newer mobile ICH - the power savings were measured at the actual component (via probes on the ICH), so I did not measure the power savings at the wall socket, although I would expect the power savings to be even greater on the other side of the power supply. So in short, yes, I think it's worth it to give it a try - the patch is pretty unintrusive, so it should be that difficult a port to do.