From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH] libata-sff: fix 32-bit PIO regression Date: Mon, 09 Feb 2009 01:18:13 +0300 Message-ID: <498F5A25.90707@ru.mvista.com> References: <200902082253.07438.sshtylyov@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]:57911 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751900AbZBHWST (ORCPT ); Sun, 8 Feb 2009 17:18:19 -0500 In-Reply-To: Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Hugh Dickins Cc: jgarzik@pobox.com, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, alan@lxorguk.ukuu.org.uk, rjw@sisk.pl Hello. Hugh Dickins wrote: >> Commit 871af1210f13966ab911ed2166e4ab2ce775b99d (libata: Add 32bit PIO support) >> caused all kind of errors on the ATAPI devices, so it's been empirically proven >> that one shouldn't read/write an extra data word when a device isn't expecting >> it already. "Don't do it then"; however still taking a chance to use 32-bit I/O >> one last time when there are exactly 3 trailing bytes. Oh, and stop pointless >> swapping bytes to and fro as well by using io*_rep() which shouldn't byte-swap. >> >> This should fix the kernel.org bug #12609. >> >> --- >> This is hopefully better replacement for Hugh Dickins most recent patch >> (http://marc.info/?l=linux-ide&m=123352294619281)... >> > > Yes, looks nice, and works for me. My only criticism would be, > minor issue unchanged by your patch, that actually "slop" isn't > unlikely enough to deserve an "unlikely" - slop of 1 or 3 is > unlikely, but slop of 2 is quite common. > I guess that's the case only for the ATAPI devices, so I'm going to keep it. MBR, Sergei