cannot use only external LCD monitor with laptop

[Adam Monsen]

I just bought a new laptop. I like to connect it to an external monitor, and configure the displays such that the laptop screen is off, and the external monitor is set to max resolution.

When I do make this change in the displays/monitors configuration, both displays go dark. After the "keep settings?" timeout expires, only the mouse cursor is visible. To use X again, I can hit CTRL-ALT-F1 to switch to a virtual terminal and pkill X... X restarts, I see the login screen and can log back into X.

The laptop is a http://zareason.com/shop/Strata-Pro-13.html. It has Intel GMA 4500MHD integrated video.

I'm using Ubuntu 11.04 (natty). Kernel is 2.6.38-8-generic-pae (32-bit). Problem also repros on non-PAE 32-bit kernel. lsmod shows the "i915" driver is loaded and "video" is using it, so I'm guessing the video driver in use is "i915". This problem repros in both Unity and GNOME Shell. Repros with both VGA and HDMI outputs. Does *not* repro in Ubuntu 10.04.2, so it makes me suspect some kernel problem in Ubuntu 11.04.

Crossposted on askubuntu.com: http://askubuntu.com/questions/49478/cannot-use-only-external-lcd-monitor-with-laptop

ProblemType: Bug
DistroRelease: Ubuntu 11.04
DistroCodename: natty
Architecture: i386

[lspci]
00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 18) (prog-if 00 [VGA controller])
        Subsystem: Giga-byte Technology Device d000

[Adam Monsen (meonkeys)]

Using the latest kernel from the kernel ppa (2.6.39.0.1~20110419) fixed the issue. Yay!

sudo add-apt-repository ppa:kernel-ppa/ppa
sudo apt-get install linux-generic-pae
sudo reboot

(I can't figure out how to resolve this issue, otherwise I would)

[Marco Biscaro (marcobiscaro2112)]

Well, in this case, the problem should be in kernel (and is probably already fixed with 2.6.39).

[Julian Wiedmann (jwiedmann)]

Adam:
Good to see that this has been fixed upstream!
Could you enable the -proposed repository (https://wiki.ubuntu.com/Testing/EnableProposed) and give kernel 2.6.38-10.44 a try? There's a lot of smaller patches queued up in that kernel, so hopefully one of them fixes this bug.

[Adam Monsen (meonkeys)]

I'll try to make time to test 2.6.38-10.44 next week.

[Julian Wiedmann (jwiedmann)]

Never mind. This seems to be a duplicate of bug 791752 - there's a test kernel in comment #6.

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in dianosing the problem. From a terminal window please run:

apport-collect 799609

and then change the status of the bug back to 'New'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.