Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1434581AbdDZCAb (ORCPT ); Tue, 25 Apr 2017 22:00:31 -0400 Received: from mail.netline.ch ([148.251.143.178]:44157 "EHLO netline-mail3.netline.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S948185AbdDZCAV (ORCPT ); Tue, 25 Apr 2017 22:00:21 -0400 Subject: Re: [PATCH 3/6] drm: fourcc byteorder: add bigendian support to drm_mode_legacy_fb_format To: =?UTF-8?B?VmlsbGUgU3lyasOkbMOk?= Cc: Daniel Vetter , dri-devel@lists.freedesktop.org, Gerd Hoffmann , amd-gfx@lists.freedesktop.org, open list References: <20170424062532.26722-1-kraxel@redhat.com> <20170424062532.26722-4-kraxel@redhat.com> <3b872a56-80b5-0c44-712f-a9517489eb24@daenzer.net> <20170425095259.GK30290@intel.com> From: =?UTF-8?Q?Michel_D=c3=a4nzer?= Message-ID: Date: Wed, 26 Apr 2017 11:00:09 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170425095259.GK30290@intel.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 714 Lines: 23 On 25/04/17 06:52 PM, Ville Syrjälä wrote: > On Tue, Apr 25, 2017 at 12:18:52PM +0900, Michel Dänzer wrote: >> On 24/04/17 03:25 PM, Gerd Hoffmann wrote: >>> +#ifdef __BIG_ENDIAN >>> + switch (bpp) { >>> + case 8: >>> + fmt = DRM_FORMAT_C8; >>> + break; >>> + case 24: >>> + fmt = DRM_FORMAT_BGR888; >>> + break; >> >> BTW, endianness as a concept cannot apply to 8 or 24 bpp formats. > > To 8bpp no, but it can easily apply to 24bpp. Any byte swapping rips apart the bytes of a 24bpp pixel, so those formats only make sense as straight array formats. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer