Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759385AbdDSD2K (ORCPT ); Tue, 18 Apr 2017 23:28:10 -0400 Received: from mail-qt0-f193.google.com ([209.85.216.193]:33264 "EHLO mail-qt0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759234AbdDSD2H (ORCPT ); Tue, 18 Apr 2017 23:28:07 -0400 MIME-Version: 1.0 In-Reply-To: References: <20170410101202.19229-1-kraxel@redhat.com> <20170410161214.305f5daf@eldfell> <1491833847.30990.77.camel@redhat.com> <20170410180941.43922e25@eldfell> <20170411103101.0497fe08@eldfell> <1492510440.27392.27.camel@redhat.com> <4230c093-6a8a-76d6-dce8-f9b2300fa70f@daenzer.net> From: Ilia Mirkin Date: Tue, 18 Apr 2017 23:28:06 -0400 X-Google-Sender-Auth: dWIdCopo1UtSV5LYjUkRyEJ2fXk Message-ID: Subject: Re: [RfC PATCH] drm: fourcc byteorder: brings header file comments in line with reality. To: =?UTF-8?Q?Michel_D=C3=A4nzer?= Cc: Gerd Hoffmann , Daniel Vetter , amd-gfx@lists.freedesktop.org, "dri-devel@lists.freedesktop.org" , open list Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id v3J3SHUm023597 Content-Length: 1444 Lines: 30 On Tue, Apr 18, 2017 at 11:19 PM, Ilia Mirkin wrote: > On Tue, Apr 18, 2017 at 9:01 PM, Michel Dänzer wrote: >> On 18/04/17 07:14 PM, Gerd Hoffmann wrote: >>> Hi, >>> >>>>> Quite true that this proves nothing. However one should note that >>>>> fbcon -> fbdev works, >>>> >>>> BTW, this supports Gerd's patch, since the KMS fbdev emulation code uses >>>> e.g. DRM_FORMAT_XRGB8888 for depth/bpp 24/32, and the fbdev API uses >>>> native endian packed colour values. >>> >>> Same is true for DRM_IOCTL_MODE_ADDFB, with depth/bpp 24/32 you'll get >>> DRM_FORMAT_XRGB8888 (only DRM_IOCTL_MODE_ADDFB2 allows userspace specify >>> fourcc formats directly). >> >> Right, and since all major Xorg drivers use DRM_IOCTL_MODE_ADDFB, >> they're effectively using DRM_FORMAT_XRGB8888 as native endianness as well. > > In the meanwhile, it has been pointed out to me that pre-nv50 display > code actually doesn't use DRM_FORMAT_* at all -- it uses some helpers > which end up advertising XR24 / AR24. However from what I can tell, > that's not a well-reasoned selection. Either way, I'm going to test > Gerd's patch, hopefully during the week, or weekend at the latest. My > current suspicion is that it will have no effect on nouveau either > way. We'll find out. (And as Michel points out, the patch doesn't actually touch anything, just comments. I originally thought it changed format -> fourcc mapping.)