Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754067AbdDMPs5 (ORCPT ); Thu, 13 Apr 2017 11:48:57 -0400 Received: from mail7.pr.hu ([87.242.0.7]:57754 "EHLO mail7.pr.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753890AbdDMPsy (ORCPT ); Thu, 13 Apr 2017 11:48:54 -0400 Subject: Re: KMS question To: Alex Deucher Cc: lkml , Maling list - DRI developers References: <2a39d6ca-afdd-bccf-264f-132736313d2b@pr.hu> From: Boszormenyi Zoltan Message-ID: Date: Thu, 13 Apr 2017 17:48:45 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Spam-Score: 1.4 (+) X-Scan-Signature: f51b28b80251e2f33265d70a8f4dc624 X-Spam-Tracer: backend.mail.pr.hu 1.4 20170413154850Z Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2276 Lines: 56 2017-04-13 17:36 keltezéssel, Alex Deucher írta: > 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? No, "xrandr --output DVI-D-1 --auto" does nothing. > > Alex >