From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH] ide: Fix ata_id_has_dword_io to return DWORD I/O support properly Date: Mon, 22 Dec 2008 23:16:36 +0300 Message-ID: <494FF5A4.9010809@ru.mvista.com> References: <494A5BBF.8000807@inf.tu-dresden.de> <494A837A.50801@garzik.org> <20081218181015.2e160d5c@lxorguk.ukuu.org.uk> <494C512B.6090304@shaw.ca> <494CF231.4020000@ru.mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from gateway-1237.mvista.com ([63.81.120.155]:58717 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1754023AbYLVUQL (ORCPT ); Mon, 22 Dec 2008 15:16:11 -0500 In-Reply-To: <494CF231.4020000@ru.mvista.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Sergei Shtylyov Cc: Robert Hancock , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Hello, I wrote: >>>> This seems like a risky assumption... >>> Its wrong on various counts >>> - ata_id_major_version can't tell early ATA versions apart >>> - on anything later than the early ISA IDE paddles (the ones that >>> basically were just bus decoders) its invisible to the drive >>> Except for legacy ISA bus controllers (and even there it is >>> questionable) I would favour simply ignoring it. >> 32-bit IO wouldn't work on any ISA controller, would it? What happens >> if you do 32-bit IO port access on something on the ISA bus? > TTBOM, depending on what's driven by device on -IOCS16, this will > translate into 2, 3, or 4 cycles at the successive addresses. In case of > the IDE data register, this should translate into one 16-bit cycle at > 0x1x0, one 8-bit cycle at 0x1x1, and one 8-bit cycle at 0x1x2 which is > of course not what anybody would want... The 8-bit cycles would be at ports 0x1x2 and 0x1x3, of course. :-) MBR, Sergei