From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: Kernel Summit request for Discussion of future of ATA (libata) and IDE Date: Tue, 05 Aug 2008 02:52:47 +0400 Message-ID: <4897883F.6020007@ru.mvista.com> References: <48976168.3020804@shaw.ca> <20080804205508.20a3f917@lxorguk.ukuu.org.uk> <48977AE1.1070402@ru.mvista.com> <20080804224309.77ffd28e@lxorguk.ukuu.org.uk> <489786A7.8060400@ru.mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from h155.mvista.com ([63.81.120.155]:3844 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751383AbYHDWwy (ORCPT ); Mon, 4 Aug 2008 18:52:54 -0400 In-Reply-To: <489786A7.8060400@ru.mvista.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: Robert Hancock , Bartlomiej Zolnierkiewicz , James Bottomley , ksummit-2008-discuss@lists.linux-foundation.org, linux-kernel , linux-ide Hello, I wrote: >>>>> supported. I couldn't track down where that bit was actually >>>>> defined in the first place, all the way back to ATA-1 it seems to >>>>> be indicated as reserved. Actually, I'm not sure why the drive >>>>> cares in the first place, it would seem like a pure host >>>>> controller issue.. >>>>> >>>> It goes back before IDE into the depths of the original compaq >>>> spec. When >>>> you have a device wired basically directly to the ISA bus (original >>>> IDE) >>>> >>> ISA has only 8/16-bit data bus, so it could not have mattered >>> there... >> >> Depends what a 32bit I/O looks like on the 16bit bus - timing wise. >> > > Two 16-bit reads at addresses 0x1x0 and 0x1x2 with the programmed > recovery time, IIRC... It's just occured to me that in case of the > 16-bit bus it should be how the drive treated the accesses at address > 0x1x2 with IOCS16 asserted that could have mattered. If it honored > them, 32-bit I/O could have worked even on a dumb ISA "controller", if > not -- no way (unless you really had *something* between the ISA and > the IDE cable). Oh, -IOCS16 is driven by device, not host. I give up then. :-) MBR, Sergei