From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760751Ab2D0RAJ (ORCPT ); Fri, 27 Apr 2012 13:00:09 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:54575 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756764Ab2D0RAH (ORCPT ); Fri, 27 Apr 2012 13:00:07 -0400 Date: Fri, 27 Apr 2012 17:59:19 +0100 From: Will Deacon To: Mike Frysinger Cc: "linux-kernel@vger.kernel.org" , "uclinux-dist-devel@blackfin.uclinux.org" , Arnd Bergmann Subject: Re: [PATCH 2/2] asm-generic: io: don't perform swab during {in,out} string functions Message-ID: <20120427165919.GD14743@mudshark.cambridge.arm.com> References: <1335523376-14695-1-git-send-email-will.deacon@arm.com> <1335523376-14695-2-git-send-email-will.deacon@arm.com> <201204271219.00596.vapier@gentoo.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201204271219.00596.vapier@gentoo.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 27, 2012 at 05:18:58PM +0100, Mike Frysinger wrote: > On Friday 27 April 2012 06:42:56 Will Deacon wrote: > > The {in,out}s{b,w,l} functions are designed to operate on a stream of > > bytes and therefore should not perform any byte-swapping, regardless of > > the CPU byte order. > > says who ? where's the agreed upon documentation for this ? This specific case is actually documented in Linux Device Drivers, but I appreciate that it's not especially clear. I had some offline discussion with Arnd where we agreed on this -- it also means that asm-generic/io.h matches what is done by bi-endian architectures providing their own accessors. Will