From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [RFC][PATCH] ahci: Add support for Promise PDC42819 Date: Thu, 04 Sep 2008 09:43:22 -0400 Message-ID: <48BFE5FA.9090006@garzik.org> 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> <65a6ef750809040459h3ffe3183nf0b5a35d15ab86e4@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:45057 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751098AbYIDNn1 (ORCPT ); Thu, 4 Sep 2008 09:43:27 -0400 In-Reply-To: <65a6ef750809040459h3ffe3183nf0b5a35d15ab86e4@mail.gmail.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Mark Nelson Cc: Mikael Pettersson , linux-ide@vger.kernel.org, linux-scsi Mark Nelson wrote: > 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 :) Well, I still think this PCI ID addition leaves open the possibility that plugging in a SAS disk could hang the system or similar misbehavior. Jeff