Failed to activate external monitor (dual monitor mode)

@jibel:
If it's related to the i915 issue, could you verify what's at 100%: is it the xserver or compiz?
Could you attach to the process eating the cpu and see if it loops inside the driver for example?

Alternatively, is this bug reproducible on a different HW configuration?

Similar issue occurs for me on an up to date Oneiric x86_64 install on a Dell Latitude E6400 but after connecting an external monitor the laptop screen goes completely back and the external monitor goes into standby after reporting no signal. Trying to switch to a virtual terminal does not reactivate the laptop screen, all I can do is hit the power button to reboot.

Attaching lspci output, let me know what else I can provide to help track down the cause.

the same issue with nouveau driver and 8400gs card and external monitor. Badly need it working to migrate from 11.04

What was the resolution of the both the internal and external monitors? Does the situation improve if the external monitor resolution is lowered?

external: 1600x1200
internal: 1280x1024

in my case it was:
external: 1920x1080
internal: 1280x800
Exactly the same issue as f1anker described.

Unfortunately won't be able to test a lower resolution until October. I am attaching lspci output, hope this helps.

I have tested with a fresh install of Oneiric on a intel core i3 system. I cannot reproduce the issue mentioned.

My internal display is resolution is 1280x800 while my external monitor is 1280x1024. The gnome control panel offers the following resolutions for the external monitor:
 - 1024x768
 - 800x600

I can run in dual monitor config with my internal resolution maxed at 1280x800 and any of the resolutions above for the external monitor.

The control panel used to propose the option to choose the maximum resolution of my external monitor (1280x1024) but it doesn't do that anymore. It has been like that for a month or so. Previously, if I had tried to use the max resolution of the external monitor, things would become very slow as if running in software. So I suppose the control panel is more clever now and only offers resolution that can be supported.

Please, test with a fresh install and a recent version of Oneiric.

HI Jay,

thanks for working on it. Just a quick question. Did you use the Mirror displays option? In mirroring it works fine for me too, but the external display can't have resolution larger internal's display. That is why you weren't able to set '1280x1024'.

I can run my external display at the same resolution as internal (1280x800) in mirroring. But things look too big for '1920x1080' display:)

Please try to disable the mirroring option to set the external display separately.

Hello ngsupb

I wasn't running in mirror mode. I was running the monitors as 2 independent surfaces; and moving application windows from one monitor to the other. This worked well on my system. No glitch or artifacts.

I also want to add that my system has a VGA external output and I used a VGA cable to connect to the VGA input of the external monitor.

The same happens also using VirtualBox. This could help testing and fixing I guess.

I have tried with some other monitor. I was able to attach it and set separate resolution for the external monitor(not mirroring) . I had both notebook and external monitor(1280 x 1024 ) running. After that I selected "off" option in the display manager for the notebook's display to turn off it in order to use the external monitor as primary monitor with the unity panel. Both displays went black. The only way was to shut down and reboot.

I can't test it with the previous display (1920x1080). With that one everything hanged and went to black right after I plug in the external display and set it as separate screen.

With the current one the issue appears after I disable internal notebook's display to use the external display only.

I have tested with the same monitor I have the issue with. It works almost fine now except of the following two issues:

1) slow. It seems worked faster on 11.04
2) when I reboot with the plugged in external monitor it doesn't work. But works when I unplug it, reboot. and plug in after boot again.

I have tested a bit more:

1) external display works fine as it is supposed when I plug in it first time. After reboot doesn't work even when I boot without it and plug in it back. I have to delete the file .config/monitors.xml after booting and plug in the display to start it working.

Anyway it is better than it was before. At least it works somehow.

2) everything works noticeably slower when both displays are enabled. After I disabled notebook's display it works at acceptable level.

Is that still an issue in Ubuntu 11.10 with all the update applied.

[Expired for compiz (Ubuntu Oneiric) because there has been no activity for 60 days.]

[Expired for compiz (Ubuntu) because there has been no activity for 60 days.]

[Expired for Unity because there has been no activity for 60 days.]