From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH 02/20] ata_piix: unify code for programming PIO and MWDMA timings Date: Mon, 21 Feb 2011 14:53:28 +0300 Message-ID: <4D625238.6040503@mvista.com> References: <20110208122314.19110.4092.sendpatchset@linux-mhg7.site> <20110208122346.19110.8441.sendpatchset@linux-mhg7.site> <4D6118DC.80505@ru.mvista.com> <20110220185958.364df4cc@lxorguk.ukuu.org.uk> <4D617CC8.3020108@ru.mvista.com> <20110220210731.0c774fa7@lxorguk.ukuu.org.uk> <4D624EBD.4080400@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 mail-ew0-f42.google.com ([209.85.215.42]:62011 "EHLO mail-ew0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755275Ab1BULys (ORCPT ); Mon, 21 Feb 2011 06:54:48 -0500 In-Reply-To: <4D624EBD.4080400@ru.mvista.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: Bartlomiej Zolnierkiewicz , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Hello. On 21-02-2011 14:38, Sergei Shtylyov wrote: >>> PIO mode is setup by different code, and it takes care of the IORDY >>> setting according to the PIO rules (and it gets called). DMA mode setup should >>> just ignore the IORDY setting as in all other sane drivers. >> Well it can't ignore it - but if you mean just keep the bit as is then > Yes, I mean this. >> that sounds sensible, have to see what the docs say happens if you ever >> set MWDMA without IORDY. > Don't think they say anything on this matter but I can't imagine that IORDY > matters for DMA. What it says is that IORDY enable bit has no effect when the fast timing bit is cleared. That's from ICH IDE PRM (29860004.pdf). WBR, Sergei