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=-8.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 5C2C0C83011 for ; Tue, 1 Dec 2020 11:22:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1D4822240 for ; Tue, 1 Dec 2020 11:22:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="eUnpfWlB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727924AbgLALV4 (ORCPT ); Tue, 1 Dec 2020 06:21:56 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:56832 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730547AbgLALVz (ORCPT ); Tue, 1 Dec 2020 06:21:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606821629; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=gQl3DpHIpoBeXGbiOMpJzHg8IZwbx7pQYj+PTlee4Ow=; b=eUnpfWlBOSCxAoyU4SFMkOjiAWMKNQvaOTDb5AyU1QpToSlvsTXD5ilV7i6w6ZQ6M2yMCB 2ckI1lMFwH1hxkMWdiCzXod67rSgV6kKy5vI7qSwc5mz8TUDN9hFqe7IcR5xePPH17/RqM KySmgA1ndm51oWYTHitsuz0gIs6orAw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-190-tkB4tctQMO2e-vCdhLOYZA-1; Tue, 01 Dec 2020 06:20:25 -0500 X-MC-Unique: tkB4tctQMO2e-vCdhLOYZA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 95A5C805BE0; Tue, 1 Dec 2020 11:20:23 +0000 (UTC) Received: from file01.intranet.prod.int.rdu2.redhat.com (file01.intranet.prod.int.rdu2.redhat.com [10.11.5.7]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1083F60BE5; Tue, 1 Dec 2020 11:20:23 +0000 (UTC) Received: from file01.intranet.prod.int.rdu2.redhat.com (localhost [127.0.0.1]) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4) with ESMTP id 0B1BKMEq003279; Tue, 1 Dec 2020 06:20:22 -0500 Received: from localhost (mpatocka@localhost) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4/Submit) with ESMTP id 0B1BKMvs003264; Tue, 1 Dec 2020 06:20:22 -0500 X-Authentication-Warning: file01.intranet.prod.int.rdu2.redhat.com: mpatocka owned process doing -bs Date: Tue, 1 Dec 2020 06:20:22 -0500 (EST) From: Mikulas Patocka X-X-Sender: mpatocka@file01.intranet.prod.int.rdu2.redhat.com To: Thomas Zimmermann cc: Daniel Vetter , linux-fbdev@vger.kernel.org, geert+renesas@glider.be, corbet@lwn.net, daniel.vetter@ffwll.ch, linux-doc@vger.kernel.org, bernie@plugable.com, dri-devel@lists.freedesktop.org, sam@ravnborg.org Subject: Re: [PATCH] fbdev: Remove udlfb driver In-Reply-To: Message-ID: References: <20201130125200.10416-1-tzimmermann@suse.de> <20201130154147.GT401619@phenom.ffwll.local> User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org On Tue, 1 Dec 2020, Thomas Zimmermann wrote: > Hi > > Am 30.11.20 um 19:39 schrieb Mikulas Patocka: > > > > > > On Mon, 30 Nov 2020, Daniel Vetter wrote: > > > > > On Mon, Nov 30, 2020 at 09:31:15AM -0500, Mikulas Patocka wrote: > > > > > > > > The framebuffer driver supports programs running full-screen directly on > > > > 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. > > > > > > Hm this should in general work on drm drivers. Without that it's clear the > > > switch-over isn't really ready yet. > > > > I fixed it with this patch two years ago: > > https://lists.freedesktop.org/archives/dri-devel/2018-June/179023.html > > > > But the patch never went through and the fb_defio feature was removed in > > the kernel 5.6 (commit d0c4fc5a4814e431c15272935c8dc973c18073aa). > > > > > > Without fb_defio, the only other possibility how to update the screen is > > the ioctl DRM_IOCTL_MODE_DIRTYFB. But this ioctl requires master mode, so > > user programs like "links -g" can't issue it. > > That's confusing. DIRTYFB is only for DRM. Yes, you're right. > And why can links not run as DRM master mode? If it renders to the terminal, > it should act like a composer. In that case it almost certainly wants master > status. > > Best regards > Thomas How can a userspace program acquire master mode without being suid? Is there some "Hello World!" program that shows how to use DRM? I'm not an expert in DRM, but if there were some tutorial+documentation, I could consider porting "links" to it. Mikulas