From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brad Campbell Subject: Re: libata dev_config call order wrong. Date: Mon, 30 Aug 2004 13:12:24 +0400 Sender: linux-ide-owner@vger.kernel.org Message-ID: <4132EF78.9000200@wasp.net.au> References: <41320DAF.2060306@wasp.net.au> <41321288.4090403@pobox.com> <413216CC.5080100@wasp.net.au> <4132198B.8000504@pobox.com> <41321F7F.7050300@pobox.com> <1093805994.28289.4.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from wasp.net.au ([203.190.192.17]:13754 "EHLO wasp.net.au") by vger.kernel.org with ESMTP id S267514AbUH3JLv (ORCPT ); Mon, 30 Aug 2004 05:11:51 -0400 In-Reply-To: <1093805994.28289.4.camel@localhost.localdomain> List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: Jeff Garzik , linux-ide@vger.kernel.org, Linux Kernel Mailing List Alan Cox wrote: > On Sul, 2004-08-29 at 19:25, Jeff Garzik wrote: > >>According to the Serial ATA docs, IDENTIFY DEVICE word 93 will be zero >>if it's Serial ATA. Who knows if that's true, given the wierd wild >>world of ATA devices. > > > You need to check if word 93 is valid first. Same with things like the > cache control word - its value is only meaningful if the drive says the > word is meaningful. I'm making some assumptions here based on information I could scrape up off the net. IDENTIFY DEVICE Word 93 support has been mandatory at least since ATA-5. ATA-5 did not have lba48 or > udma/66. SATA->PATA bridge boards support > udma/33 and thus must emulate an 80 conductor cable. Thus, any device capable of lba48 (and these are the ones that trigger the > 200 sector problem) must (according to the ATA-5 and up standard) support correct use of the IDENTIFY DEVICE word 93 register. Given that the SATA->PATA bridge boards support 80 pin detection, then bit 13 of word 93 must be high on any drive that supports lba48, and given the *current* sata spec states that word 93 must be zero, we should be able to use this detection method. Now, remember I have been an "ATA researcher" for about 4 hours now, please feel free to belt me with the wet salmon of enlightenment and point out the flaw in my logic. Otherwise, when I get home this evening I'm going to have a crack and getting this working. Regards, Brad