Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932222AbcLHMP7 (ORCPT ); Thu, 8 Dec 2016 07:15:59 -0500 Received: from mail-io0-f193.google.com ([209.85.223.193]:33276 "EHLO mail-io0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750827AbcLHMP6 (ORCPT ); Thu, 8 Dec 2016 07:15:58 -0500 MIME-Version: 1.0 In-Reply-To: <20161208101005.6ufl3d4qvwprosju@phenom.ffwll.local> References: <1479888193-23908-1-git-send-email-tomi.valkeinen@ti.com> <1481158879.26959.41.camel@kernel.crashing.org> <20161208101005.6ufl3d4qvwprosju@phenom.ffwll.local> From: Geert Uytterhoeven Date: Thu, 8 Dec 2016 13:15:56 +0100 X-Google-Sender-Auth: QDZLxS2UXj4GPxXLaRFH2YwRyFE Message-ID: Subject: Re: [RFC PATCH 0/3] staging: remove fbdev drivers To: Benjamin Herrenschmidt , Tomi Valkeinen , Linux Fbdev development list , DRI Development , Greg Kroah-Hartman , Thomas Petazzoni , =?UTF-8?Q?Noralf_Tr=C3=B8nnes?= , Sudip Mukherjee , Teddy Wang , Arnaud Patard , "linux-kernel@vger.kernel.org" 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-Length: 2668 Lines: 61 On Thu, Dec 8, 2016 at 11:10 AM, Daniel Vetter wrote: > On Thu, Dec 08, 2016 at 12:01:19PM +1100, Benjamin Herrenschmidt wrote: >> On Wed, 2016-11-23 at 10:03 +0200, Tomi Valkeinen wrote: >> > Since the fbdev framework is in maintenance mode and all new display drivers >> > should be made with the DRM framework, remove the fbdev drivers from staging. >> > >> > Note: the patches are created with git format-patch -D, so they can't be >> > applied. Only for review. >> >> I missed the discussion where this decision was made, I admit I am >> unimpressed by it. >> >> DRM drivers don't strike me as suitable for small/slow cores with dumb >> framebuffers or simple 2D only accel, such as the one found in the ASpeed >> BMCs. > > We have a helper for simple drivers now, if you take into account the > massive helper libraries for everything that comes along with drm I expect > if even dumb panels behind slow spi buses drm is now the more suitable > subsytem. This has been going on your years: 1. Fbdev is obsolete, everybody should use DRM instead! 2. Can you please point me to a small sample driver for a dumb frame buffer? 3. Several are being written, but none of them is upstream yet. 4. Goto 1. >> With drmfb you basically have to shadow everything into memory & copy >> over everything, and locks you out of simple 2D accel. For a simple text >> console the result is orders of magnitude slower and memory hungry than >> a simple fbdev. > > Not true, we have full fbdev emulation, and drivers can implement the 2d > accel in there. And a bunch of them do. It's just that most teams decided > that this is pointless waste of their time.j > >> At least that was the case last I looked at the DRM stuff with Dave, >> maybe things have changed... >> >> Not everything has a powerful 3D GPU. > > That's correct, and drm can cope. And compared to fbdev there's a very > active community who improves&refactors it every kernel release to make it > even better. Since about 2 years (when atomic landed) we merge new drivers at > a rate of 2-3 per kernel release, and those new drivers get ever simpler > and smaller thanks to all this work. You mean the kind of refactoring that causes severe merge conflicts between drm-next and Linus' tree about every single day? (sorry, couldn't resist ;-) Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds