From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Mark Nelson" Subject: Re: [RFC][PATCH] ahci: Add support for Promise PDC42819 Date: Thu, 4 Sep 2008 21:59:29 +1000 Message-ID: <65a6ef750809040459h3ffe3183nf0b5a35d15ab86e4@mail.gmail.com> References: <65a6ef750809020403i52228319u9e3197e4062941bc@mail.gmail.com> <48BD2136.1020101@garzik.org> <65a6ef750809020455q7b7ee6a8jc404b4970f660c50@mail.gmail.com> <18621.11426.870514.781750@harpo.it.uu.se> <65a6ef750809020521wfaca733r8253795860b95f4@mail.gmail.com> <48BFBA5E.5050300@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <48BFBA5E.5050300@garzik.org> Content-Disposition: inline Sender: linux-scsi-owner@vger.kernel.org To: Jeff Garzik Cc: Mikael Pettersson , linux-ide@vger.kernel.org, linux-scsi List-Id: linux-ide@vger.kernel.org On Thu, Sep 4, 2008 at 8:37 PM, Jeff Garzik wrote: > Mark Nelson wrote: >> >> On Tue, Sep 2, 2008 at 10:08 PM, Mikael Pettersson wrote: >>> >>> Mark Nelson writes: >>> > On Tue, Sep 2, 2008 at 9:19 PM, Jeff Garzik wrote: >>> > > Mark Nelson wrote: >>> > >> >>> > >> Add an appropriate entry for the Promise PDC42819 controller. It >>> has an >>> > >> AHCI mode and seems to work correctly with board_ahci. >>> > >> >>> > >> This chip is found on Promise's FastTrak TX2650 (2 port) and TX4650 >>> (4 >>> > >> port) >>> > >> software-based RAID cards (for which there is a binary driver, >>> t3sas) and >>> > >> can be found on some motherboards, for example the MSI K9A2 >>> Platinum, >>> > >> which calls the chip a Promise T3 controller. >>> > >> >>> > >> Signed-off-by: Mark Nelson >>> > >> --- >>> > >> Apparently this chip also supports SAS disks, will these work with >>> the >>> > >> ahci driver (I've only tested with normal desktop SATA disks)? >>> > > >>> > > ahci is definitely SATA-only, so I wonder how they modified AHCI to >>> support >>> > > SAS transport... >>> > >>> > That is a good question. From my understanding the controller is a SAS >>> > controller that can drive SATA disks (as I guess all SAS controllers >>> can >>> > do...). Could it be that the controller can be setup to act as an AHCI >>> > SATA controller or if the right registers are poked a SAS controller? >>> >>> Based on how the sata_promise-supported chips work I'd guess that they >>> have dual programming interfaces with AHCI for JBOD SATA and a native >>> one (perhaps just additional control registers) for SAS and raid. >>> >> >> That's interesting; and makes sense. I'm guessing that we won't end up >> with an open source driver that can do SAS on these chips then... But >> for now at least we can use them as SATA controllers and if Promise >> wants to come to the table with specs or datasheets they can in the >> future. I'm just happy to be able to use my eSATA ports (and perhaps >> the possibility of getting my hard disk off the SB600, although I should >> benchmark both controllers before jumping to any conclusions). > > FWIW, I'll poke my Promise contacts, but they have gone mostly silent in the > past year, so don't get your hopes up... Thanks Jeff! No need for hope - we have ahci now :) (speaking of which, should I resend the patch without the RFC?) Mark