From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH 2/2 resend] libata-sff: avoid byte swapping in ata_sff_data_xfer() Date: Tue, 07 Apr 2009 13:15:08 +0400 Message-ID: <49DB199C.3040305@ru.mvista.com> References: <200902152230.38271.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]:32226 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753415AbZDGJPP (ORCPT ); Tue, 7 Apr 2009 05:15:15 -0400 In-Reply-To: <200902152230.38271.sshtylyov@ru.mvista.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: jgarzik@pobox.com Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, alan@lxorguk.ukuu.org.uk Hello, I wrote: > Handling of the trailing byte in ata_sff_data_xfer() is suboptimal bacause: > > - it always initializes the padding buffer to 0 which is not really needed in > both the read and write cases; > > - it has to use memcpy() to transfer a single byte from/to the padding buffer; > > - it uses io{read|write}16() accessors which swap bytes on the big endian CPUs > and so have to additionally convert the data from/to the little endian format > instead of using io{read|write}16_rep() accessors which are not supposed to > change the byte ordering. > > Signed-off-by: Sergei Shtylyov Jeff, have you forgotten about this one? MBR, Sergei