From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965132AbWEOS1u (ORCPT ); Mon, 15 May 2006 14:27:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965134AbWEOS1u (ORCPT ); Mon, 15 May 2006 14:27:50 -0400 Received: from rtsoft2.corbina.net ([85.21.88.2]:7076 "HELO mail.dev.rtsoft.ru") by vger.kernel.org with SMTP id S965130AbWEOS1s (ORCPT ); Mon, 15 May 2006 14:27:48 -0400 Message-ID: <4468C7DF.7090603@ru.mvista.com> Date: Mon, 15 May 2006 22:26:39 +0400 From: Sergei Shtylyov Organization: MontaVista Software Inc. User-Agent: Mozilla/5.0 (X11; U; Linux i686; rv:1.7.2) Gecko/20040803 X-Accept-Language: ru, en-us, en-gb MIME-Version: 1.0 To: Alan Cox CC: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Assorted bugs in the PIIX drivers References: <1132929808.3298.18.camel@localhost.localdomain> <44689A54.4020307@ru.mvista.com> <1147708783.26686.69.camel@localhost.localdomain> In-Reply-To: <1147708783.26686.69.camel@localhost.localdomain> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello. Alan Cox wrote: > On Llu, 2006-05-15 at 19:12 +0400, Sergei Shtylyov wrote: >> For PIO2+ actually, according to Intel's PRM (29860004.pdf), and it's said >> to have no effect in the lower modes. This is actually not very correct since >> when one issues Set Transfer Mode ATA command with the value (8 + PIOn), this >> means select PIO _flow control_ mode n, so -IORDY is assumed to be in use. > PIO2 depends on the drive (there is a drive parameter telling you the > highest timing clock you can do with/without IORDY Yes. But when you're setting any _explicit_ PIO mode with Set Features command, you're tell the drive to use -IORDY at the same time. >>> I'm also not clear if the "no MWDMA0" list has been updated correctly >>> for the newer chipsets. >> What is/was the point for keeping MW DMA 0 support anyway? On PIIX, it's >> greatly slowed down (600 vs 480 ns cycle) and was never "offically" supported >> by Intel. > Some old old drives only do MWDMA0. The Intel docs I have here don't > describe it in any way as "unsupported", They just don't describe it, period. :-) > merely broken on some ICH variants. ICH errata #55: "Note that DMA Mode-0 is an unsupported mode of the ICH." > Alan MBR, Sergei