External screen on mini-DisplayPort no longer detected

[Bruno Girin]

My laptop has a mini-DisplayPort and an HDMI port to which I can connect external monitors. When I plug it in into the HDMI port, it is properly recognised but when I plug it into the mini-DisplayPort, Unity fails to recognise the display. This used to work in 12.10.

Steps to reproduce:
1. Plug in the external display to the HDMI port via an HDMI adapter: the Unity display extends to the second monitor
2. Plug the same display to the mini-DisplayPort adapter: the screen stay blank
3. Open System Settings -> Displays: the external monitor is no detected.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: unity 7.0.0daily13.04.18~13.04-0ubuntu1
ProcVersionSignature: Ubuntu 3.8.0-18.28-generic 3.8.6
Uname: Linux 3.8.0-18-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.9.2-0ubuntu8
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
Date: Thu Apr 18 14:37:20 2013
DistUpgraded: 2013-03-24 16:04:44,678 DEBUG enabling apt cron job
DistroCodename: raring
DistroVariant: ubuntu
DkmsStatus: virtualbox, 4.2.10: added
GraphicsCard:
 Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0126] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:21e8]
InstallationDate: Installed on 2013-03-24 (24 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5)
MachineType: LENOVO 12942NG
MarkForUpload: True
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-18-generic root=UUID=aeda5fea-792c-4b75-b1f9-572ad71afcbc ro quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: Upgraded to raring on 2013-03-24 (24 days ago)
dmi.bios.date: 06/20/2011
dmi.bios.vendor: LENOVO
dmi.bios.version: 8MET22WW (1.22 )
dmi.board.asset.tag: Not Available
dmi.board.name: 12942NG
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr8MET22WW(1.22):bd06/20/2011:svnLENOVO:pn12942NG:pvrThinkPadX1:rvnLENOVO:rn12942NG:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 12942NG
dmi.product.version: ThinkPad X1
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.9~daily13.04.18.1~13.04-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.43-0ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 9.1.1-0ubuntu2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 9.1.1-0ubuntu2
version.xserver-xorg-core: xserver-xorg-core 2:1.13.3-0ubuntu6
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.3-0ubuntu2b2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.1.0-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.21.6-0ubuntu3
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.7-0ubuntu1
xserver.bootTime: Thu Apr 18 13:53:57 2013
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.13.3-0ubuntu6
xserver.video_driver: intel

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Mauro Monti (mmonti)]

Same problem for me. It was working with a fresh install, but it stopped working with some updates.

[Dominik (0-mail-a)]

same problem for me. i have a samsung syncmaster p2370hd that i connected using a minidisplayport to vga adapter under ubuntu 12.04 where everything worked fine. under 13.04 it gets not recognised :(

[Ivan Yaru (ivanyaru)]

I have the same issue. I'm running 13.04 on a MacBookPro (9,1). I connect to external displays using mini DisplayPort adapters. mini DisplayPort to DVI works fine. However, when using mini DisplayPort to VGA, the external display is not detected.