Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753428AbdDJORa convert rfc822-to-8bit (ORCPT ); Mon, 10 Apr 2017 10:17:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36894 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752963AbdDJOR3 (ORCPT ); Mon, 10 Apr 2017 10:17:29 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 37BD019CBD1 Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=kraxel@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 37BD019CBD1 Message-ID: <1491833847.30990.77.camel@redhat.com> Subject: Re: [RfC PATCH] drm: fourcc byteorder: brings header file comments in line with reality. From: Gerd Hoffmann To: Pekka Paalanen Cc: dri-devel@lists.freedesktop.org, open list , amd-gfx@lists.freedesktop.org, Daniel Vetter Date: Mon, 10 Apr 2017 16:17:27 +0200 In-Reply-To: <20170410161214.305f5daf@eldfell> References: <20170410101202.19229-1-kraxel@redhat.com> <20170410161214.305f5daf@eldfell> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Mime-Version: 1.0 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Mon, 10 Apr 2017 14:17:29 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 820 Lines: 22 Hi, > which software have you used as representative of "reality"? ppc64 (big endian) virtual machine, running with qemu stdvga & bochs-drm driver. Xorg with modesetting driver uses DRM_FORMAT_XRGB8888 (one and only format supported by bochs-drm), and we have to interpret that in bigendian byte order on the host side to get a correct display. Didn't try wayland. Can do, but will take a while. Don't have a wayland-capable guest install at hand, and installing one takes a while because I don't have a physical pseries and emulation is slooooww. > To solve that problem, we would like to know if anything existing would > break for each possible solution, but no developers using BE have really > turned up. That is part of the problem. And even ppc is moving to little endian these days ... cheers, Gerd