From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.gna.ch (darkcity.gna.ch [195.226.6.51]) by ozlabs.org (Postfix) with ESMTP id 7B021B70A3 for ; Sat, 2 Oct 2010 02:30:42 +1000 (EST) Subject: Re: Introduce support for little endian PowerPC From: Michel =?ISO-8859-1?Q?D=E4nzer?= To: Benjamin Herrenschmidt In-Reply-To: <1285935283.2463.78.camel@pasglop> References: <1285916771-18033-1-git-send-email-imunsie@au1.ibm.com> <2C5357FA-F87F-457E-B5C1-0DCC5A842DE7@kernel.crashing.org> <1285935283.2463.78.camel@pasglop> Content-Type: text/plain; charset="UTF-8" Date: Fri, 01 Oct 2010 18:20:41 +0200 Message-ID: <1285950041.15020.272.camel@thor.local> Mime-Version: 1.0 Cc: paulus@samba.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Ian Munsie List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fre, 2010-10-01 at 22:14 +1000, Benjamin Herrenschmidt wrote:=20 >=20 > Now, the main reasons in practice are anything touching graphics. >=20 > There's quite a few IP cores out there for SoCs that don't have HW > swappers, and -tons- of more or less ugly code that can't deal with non > native pixel ordering (hell, even Xorg isn't good at it, we really only > support cards that have HW swappers today). That's not true. Even the radeon driver doesn't really need the HW swappers anymore with KMS. > There's an even bigger pile of application code that deals with graphics > without any regard for endianness and is essentially unfixable. Out of curiosity, what kind of APIs are those apps using? X11 and OpenGL have well-defined semantics wrt endianness, allowing the drivers to handle any necessary byte swapping internally, and IME the vast majority of apps handle this correctly. --=20 Earthling Michel D=C3=A4nzer | http://www.vmware.c= om Libre software enthusiast | Debian, X and DRI developer From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753167Ab0JAQUx (ORCPT ); Fri, 1 Oct 2010 12:20:53 -0400 Received: from darkcity.gna.ch ([195.226.6.51]:34175 "EHLO mail.gna.ch" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753092Ab0JAQUv convert rfc822-to-8bit (ORCPT ); Fri, 1 Oct 2010 12:20:51 -0400 X-Quarantine-ID: X-Amavis-Alert: BAD HEADER, Improper folded header field made up entirely of whitespace (char 09 hex): Face: ...MWASAkVVViQjzP\n jycPrvgA\n\t\n R1goSzOnkp14Y[...] Subject: Re: Introduce support for little endian PowerPC From: Michel =?ISO-8859-1?Q?D=E4nzer?= To: Benjamin Herrenschmidt Cc: Josh Boyer , linuxppc-dev@lists.ozlabs.org, paulus@samba.org, linux-kernel@vger.kernel.org, Ian Munsie In-Reply-To: <1285935283.2463.78.camel@pasglop> References: <1285916771-18033-1-git-send-email-imunsie@au1.ibm.com> <2C5357FA-F87F-457E-B5C1-0DCC5A842DE7@kernel.crashing.org> <1285935283.2463.78.camel@pasglop> Face: 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 jycPrvgA R1goSzOnkp14YCYHsp7QJHAS5QcXDqG1jBxdSITVgBNkBTFloj88Q/gMkFcuItYiQPUCBGc2xh5drsD/wGZrgsgDOE4ZAAAAABJRU5ErkJggg== Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Fri, 01 Oct 2010 18:20:41 +0200 Message-ID: <1285950041.15020.272.camel@thor.local> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fre, 2010-10-01 at 22:14 +1000, Benjamin Herrenschmidt wrote: > > Now, the main reasons in practice are anything touching graphics. > > There's quite a few IP cores out there for SoCs that don't have HW > swappers, and -tons- of more or less ugly code that can't deal with non > native pixel ordering (hell, even Xorg isn't good at it, we really only > support cards that have HW swappers today). That's not true. Even the radeon driver doesn't really need the HW swappers anymore with KMS. > There's an even bigger pile of application code that deals with graphics > without any regard for endianness and is essentially unfixable. Out of curiosity, what kind of APIs are those apps using? X11 and OpenGL have well-defined semantics wrt endianness, allowing the drivers to handle any necessary byte swapping internally, and IME the vast majority of apps handle this correctly. -- Earthling Michel Dänzer | http://www.vmware.com Libre software enthusiast | Debian, X and DRI developer