Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753467AbdDMPhu (ORCPT ); Thu, 13 Apr 2017 11:37:50 -0400 Received: from mail-qk0-f196.google.com ([209.85.220.196]:33107 "EHLO mail-qk0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751709AbdDMPhq (ORCPT ); Thu, 13 Apr 2017 11:37:46 -0400 MIME-Version: 1.0 In-Reply-To: References: <2a39d6ca-afdd-bccf-264f-132736313d2b@pr.hu> From: Ilia Mirkin Date: Thu, 13 Apr 2017 11:37:45 -0400 X-Google-Sender-Auth: Cj7gH-h2szx2hLoLBhiaL4lwvLY Message-ID: Subject: Re: KMS question To: Alex Deucher Cc: Boszormenyi Zoltan , lkml , Maling list - DRI developers 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 v3DFbrYf017380 Content-Length: 2328 Lines: 55 On Thu, Apr 13, 2017 at 11:36 AM, Alex Deucher wrote: > On Thu, Apr 13, 2017 at 11:03 AM, Boszormenyi Zoltan wrote: >> 2017-04-13 16:05 keltezéssel, Alex Deucher írta: >>> >>> On Thu, Apr 13, 2017 at 9:03 AM, Boszormenyi Zoltan wrote: >>>> >>>> Hi, >>>> >>>> how can I disable the behaviour in the KMS drivers >>>> that enables all outputs at once? >>>> >>>> It is very annoying that on a POS machine with an >>>> 1024x768 LVDS and a 800x480 secondary monitor (both built-in) >>>> the KMS driver wakes up both. Then the framebuffer console >>>> and plymouth use both screens, making the primary output >>>> very odd with only the top-left part used by the boot splash. >>>> >>>> I would like the boot splash to be shown only on the primary >>>> output at its full resolution instead of on all outputs using >>>> the smallest common rectangle. >>>> >>>> Is there a kernel command line configuration that achieves this? >>>> >>>> The device in question uses the gma500 kernel driver but the same >>>> behaviour is observed with the i915 and radeon drivers. >>>> >>> >>> The problem is fbdev is not multi-head aware. The fbdev emulation in >>> the KMS drivers attempts to light up all monitors so that something >>> shows up on all heads. If you really want different per head >>> configurations, you need to use the KMS API directly. As a >>> workaround, you can use the kernel command line to disable the output >>> you don't want to be lit up. See: >>> https://wiki.archlinux.org/index.php/kernel_mode_setting >>> for more info. basically add video=TV-1:d to disable the output in >>> question. Replace TV-1 with whatever connector you want to disable. >> >> >> I tried adding video=DVI-D-1:d to the kernel command line. >> >> The effect is while the second output is indeed disabled, the >> framebuffer console still takes the second output's resolution >> into account and the boot splash is still using only the top-left >> 800x480 part of the 1024x768 primary screen. >> >> Also, the secondary screen got disabled also in X which is not desired. >> Can I wake it up under X somehow? This device is using the modesetting >> DDX driver. > > Can you enable it via randr? I think the video= based disable forces the connector to be disabled irrevocably. -ilia