From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] AHCI PCI ID for MacBook Pro Date: Sat, 10 Feb 2007 09:03:55 -0500 Message-ID: <45CDD0CB.2070608@gmail.com> References: <82530.66623.qm@web25412.mail.ukl.yahoo.com> <200702091527.08447.rootkit85@yahoo.it> <1171032893.8134.13.camel@localhost> <200702091839.52316.rootkit85@yahoo.it> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from wx-out-0506.google.com ([66.249.82.233]:49227 "EHLO wx-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932113AbXBJOEV (ORCPT ); Sat, 10 Feb 2007 09:04:21 -0500 Received: by wx-out-0506.google.com with SMTP id h31so1172728wxd for ; Sat, 10 Feb 2007 06:04:20 -0800 (PST) In-Reply-To: <200702091839.52316.rootkit85@yahoo.it> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Matteo Croce Cc: linux-ide@vger.kernel.org Matteo Croce wrote: > On Friday 09 February 2007 15:54:53 you wrote: >> On Fri, 2007-02-09 at 15:27 +0100, Matteo Croce wrote: >>> + { PCI_VDEVICE(INTEL, 0x27c4), board_ahci }, /* ICH7M */ >> Wasn't this PCI ID proposed for addition a while ago, and subsequently >> rejected? Or am I missing something? > > rejected? why? Ah... right. All ICH7 R/M silicons can be put into either IDE or AHCI mode. Which mode is used is currently determined by BIOS. If BIOS puts the controller into ahci mode on boot, ahci is attached; otherwise, ata_piix. This sometimes reduces confusion level but more importantly in some cases it's not possible to use the other mode because PCI resource allocation is upto BIOS and it's not guaranteed to allocate all the needed resources for the mode not in use. Till now, the policy to follow BIOS setting has worked well enough. Most desktop BIOSen give choice between the two modes anyway. There have been some cases where some desktops and many notebooks where the silicon itself is capable of ahci but BIOS doesn't allow it. It seems Mac is one of them. -- tejun