From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C6B9DC83011 for ; Tue, 1 Dec 2020 08:03:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 70C862085B for ; Tue, 1 Dec 2020 08:03:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727369AbgLAIDQ (ORCPT ); Tue, 1 Dec 2020 03:03:16 -0500 Received: from mx2.suse.de ([195.135.220.15]:44200 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726120AbgLAIDQ (ORCPT ); Tue, 1 Dec 2020 03:03:16 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id B06C5AC2F; Tue, 1 Dec 2020 08:02:33 +0000 (UTC) To: Mikulas Patocka Cc: daniel.vetter@ffwll.ch, sam@ravnborg.org, geert+renesas@glider.be, bernie@plugable.com, corbet@lwn.net, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-doc@vger.kernel.org References: <20201130125200.10416-1-tzimmermann@suse.de> From: Thomas Zimmermann Subject: Re: [PATCH] fbdev: Remove udlfb driver Message-ID: <336a41ef-1e49-6799-1bfd-06fb42419fb8@suse.de> Date: Tue, 1 Dec 2020 09:02:32 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="jETQjiqHPQ4ssdDqzOpb6mlFH3OMj7CrU" Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --jETQjiqHPQ4ssdDqzOpb6mlFH3OMj7CrU Content-Type: multipart/mixed; boundary="MZI83QV9cxoq5fqjHDyDJ9hsnk2pJTnp6"; protected-headers="v1" From: Thomas Zimmermann To: Mikulas Patocka Cc: daniel.vetter@ffwll.ch, sam@ravnborg.org, geert+renesas@glider.be, bernie@plugable.com, corbet@lwn.net, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-doc@vger.kernel.org Message-ID: <336a41ef-1e49-6799-1bfd-06fb42419fb8@suse.de> Subject: Re: [PATCH] fbdev: Remove udlfb driver References: <20201130125200.10416-1-tzimmermann@suse.de> In-Reply-To: --MZI83QV9cxoq5fqjHDyDJ9hsnk2pJTnp6 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable Hi Am 30.11.20 um 15:31 schrieb Mikulas Patocka: >=20 >=20 > On Mon, 30 Nov 2020, Thomas Zimmermann wrote: >=20 >> Udlfb has been superseded by DRM's udl. The DRM driver is better by >> any means and actively maintained. Remove udlfb. >=20 > Hi >=20 > I am using udlfb and it's definitely better than the DRM driver. The DR= M > driver will crash the kernel if you unplug the device while Xorg is > running. The framebuffer driver doesn't crash in this case. (I have a c= at > and the cat sometimes unplugs cables and I don't want to reboot the sys= tem > because of it :-) What's the exact STR here? Just open the /dev/fb* and pull the cable. Do I need a cat? :) > The framebuffer driver is faster, it keeps back buffer and updates only= > data that differ between the front and back buffer. The DRM driver does= n't > have such optimization, it will update everything in a given rectangle = - > this increases USB traffic and makes video playback more jerky. That's not quite true, but not false either. I think we could optimize=20 what we have. >=20 > The framebuffer driver supports programs running full-screen directly o= n > the framebuffer console, such as web browser "links -g", image viewer > "fbi", postscript+pdf viewer "fbgs", ZX Spectrum emulator "fuse-sdl", > movie player "mplayer -vo fbdev". The DRM driver doesn't run them. I would expect that most programs have an SDL2 backend. (?) IIRC SDL2=20 has support for DRI interfaces. >=20 > If you seach for someone to maintain the framebuffer driver, I can do i= t. I'm looking for reasons why udlfb is still around. What I got from this=20 thread is the possible crash and a lack of DRM's fbdev performance.=20 Thanks for the feedback. Best regards Thomas >=20 > Mikulas >=20 >=20 >> Signed-off-by: Thomas Zimmermann >> --- >> CREDITS | 5 + >> Documentation/fb/index.rst | 1 - >> Documentation/fb/udlfb.rst | 162 --- >> MAINTAINERS | 9 - >> drivers/video/fbdev/Kconfig | 17 +- >> drivers/video/fbdev/Makefile | 1 - >> drivers/video/fbdev/udlfb.c | 1994 --------------------------------= -- >> 7 files changed, 6 insertions(+), 2183 deletions(-) >> delete mode 100644 Documentation/fb/udlfb.rst >> delete mode 100644 drivers/video/fbdev/udlfb.c >=20 --=20 Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 N=C3=BCrnberg, Germany (HRB 36809, AG N=C3=BCrnberg) Gesch=C3=A4ftsf=C3=BChrer: Felix Imend=C3=B6rffer --MZI83QV9cxoq5fqjHDyDJ9hsnk2pJTnp6-- --jETQjiqHPQ4ssdDqzOpb6mlFH3OMj7CrU Content-Type: application/pgp-signature; name="OpenPGP_signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="OpenPGP_signature" -----BEGIN PGP SIGNATURE----- wsF5BAABCAAjFiEExndm/fpuMUdwYFFolh/E3EQov+AFAl/F+JgFAwAAAAAACgkQlh/E3EQov+BM LQ//Vg6mZxBQkKGfk81NgT+i4Xu2RchOn+gnnNMFhpIvLKmvbOtIntaqSJu0Iqy7xWTqarZW3Qrr pzGxGfnBvIb6YcrEXLY+pwnJsVHy8sTSMYjX2sFCcBjsur9IT1mXyNOUyI6KY/4RvdSSFXZkiBBX HWUuFwCqfdKh314jzLKMO/yy7THc0SwX5JUGzm7KSqg+wZjelDMUu1ztO5QfQ5HpoSxgHX93MkNI LarMTG53CD3F7fV8pJpDWit2LOxhGOwHHUCNOPGyKMpO5Fr1p1grrqc9D6w/IDdyyLonaRNCJoHt BZc/aKRUIJ17yJsBU1N63Tm9Qwcps8lT3OmOw9qXCzVZf/AQSj3nKpV6iMVlErHtRc8n5CaTmUB9 2uulKUxYyaGS9mOpNJhF4g6CdmJc0DrUIaIRtdr9cdspC0oufYtAdSnDQhB5mVD+dGZSvHjMurNA Fiy9KnWAWiJWT2vHgVv8YE1JRGrt4DxTtL9TjWhxKcS6WCHzPBKW26p86jrPamw91ub/PsK3/Xzs juQAmNdYZpwg/1r1dwmWztORHgiqyl+SHjAo4s9RBT7dCCz2N9pb4EGIj0XNjYTeyifYyhrHMIxc rxkEotDoYh28s8MvB2zaEgY5QEDguGNt1kZkImsy2WCQCRG68rc42SUkzSpj7dBX68287w2gQfrQ kKo= =42KM -----END PGP SIGNATURE----- --jETQjiqHPQ4ssdDqzOpb6mlFH3OMj7CrU--