From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: Playing with SATA NCQ Date: Sun, 29 May 2005 12:59:14 -0400 Message-ID: <4299F4E2.4020305@pobox.com> References: <20050526140058.GR1419@suse.de> <1117382598.4851.3.camel@localhost.localdomain> <4299EF16.2050208@pobox.com> <1117385429.4851.8.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.dvmed.net ([216.237.124.58]:30439 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S261290AbVE2Q7S (ORCPT ); Sun, 29 May 2005 12:59:18 -0400 In-Reply-To: <1117385429.4851.8.camel@localhost.localdomain> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Erik Slagter Cc: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, Jens Axboe Erik Slagter wrote: > On Sun, 2005-05-29 at 12:34 -0400, Jeff Garzik wrote: > >>>>Now, this patch is not complete. It should work and work well, but error >>>>handling isn't really tested or finished yet (by any stretch of the >>>>imagination). So don't use this on a production machine, it _should_ be >>>>safe to use on your test boxes and for-fun workstations though (I run it >>>>here...). I have tested on ich6 and ich7 generation ahci, and with >>>>Maxtor and Seagate drives. >>> >>>Is this supposed to work on ICH7 in legacy mode as well? >> >>Nope. ata_piix does not support NCQ (because the h/w doesn't support). > > > If I understand this correctly: NCQ does not work on ICH7 in native mode > (using ata_piix) because in this mode there is no NCQ available, right? To be more specific, there are these modes: legacy mode no NCQ combined mode no NCQ native mode no NCQ AHCI mode NCQ >>>Another question: is there a fundamental problem to have the ICH6/7 >>>enabled AHCI mode by the kernel instead of the BIOS? I know some BIOSes >>>don't offer the choice to enable AHCI (like mine :-(). >> >>Not a problem. You just don't get to use AHCI and such. > > > Huh? > > My question was if there is a fundamental reason why the AHCI mode of > the ICH6/7 must be enabled by the BIOS, is there a reason why the kernel > doesn't do it, or can't do it? The BIOS sets up PCI resources necessary to use AHCI mode. Jeff