From mboxrd@z Thu Jan 1 00:00:00 1970 From: Riki Oktarianto Subject: Re: [PATCH] Add quirk to set AHCI mode on ICH boards Date: Sat, 10 Nov 2007 05:38:02 +0700 Message-ID: <20071109223802.GA23004@ceren> References: <20071109020235.GA2031@ceren> <20071109023129.GA25581@havoc.gtf.org> <4733D421.7000505@rtr.ca> <20071109034622.GB25581@havoc.gtf.org> <20071109120425.543971bf@the-village.bc.nu> <4734736C.5060003@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from rv-out-0910.google.com ([209.85.198.185]:22641 "EHLO rv-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753233AbXKIWi2 (ORCPT ); Fri, 9 Nov 2007 17:38:28 -0500 Received: by rv-out-0910.google.com with SMTP id k20so582493rvb for ; Fri, 09 Nov 2007 14:38:28 -0800 (PST) Content-Disposition: inline In-Reply-To: <4734736C.5060003@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: =?iso-8859-1?B?VPZy9ms=?= Edwin Cc: Jeff Garzik , Mark Lord , linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Alan Cox , linux-ide@vger.kernel.org On Fri, Nov 09, 2007 at 04:49:16PM +0200, T=F6r=F6k Edwin wrote: > There is one problem with force enabling ahci. You'll loose the CDROM= on > Dell laptops. > Prior to force-enabling ahci there is one "device" that sees the 2 sa= ta > channels, and the 2 ide channels. > When you force-enable ahci, this device becomes the ahci controller (= it > changes the device id), > and the IDE controller will appear as a separate new device (with > another device id), but it is disabled. >=20 > There are registers on the ICH7 that allows you to set enabled/disabl= ed > status, but according to the documentation you should not enable a > device after it has been disabled. In practice I couldn't get the CDR= OM > to get re-enabled: > * either nothing happend > * spurious irqs were sent that nobody handles, unless I used irq=3Dpo= ll; > but still no cdrom. >=20 > Force-enabling AHCI, and not trying to enable the CDROM works, althou= gh > I occasionally got NCQ errors. >=20 > For a (long) discussion see this thread on the powertop mailing list: > http://www.bughost.org/pipermail/power/2007-June/000533.html > http://www.bughost.org/pipermail/power/2007-June/000573.html >=20 > And there is also another slightly different approach: > http://mjg59.livejournal.com/76062.html >=20 > Best regards, > --Edwin >=20 In the MacBook, after enabling ahci the IDE controller also appeared as= a separate new device, but it is enabled and handled correctly by piix. I haven't got any problem, even suspend/resume works fine. Lucky us who got the ABAR mapped by the BIOS... --=20 Riki Oktarianto