15

I have installed the xserver-xorg-video-dummy-hwe-18.04 to let I use the VNC without needs to connect HDMI cable to my ubuntu machine.

I followed the Topic here, and successfully able to use VNC connect to Ubuntu machine without plugged-in monitor.

However, there are side effect is that, if I connect the HDMI cable to the ubuntu machine, it will display _ (black screen with cursor blinking at the top) and not show lightdm login screen as expected.

If I remove /etc/X11/xorg.conf from directory, reboot, I can now back using the monitor plugged-in.

Question

Are there possible to able to use video-dummy with/without monitor at the same time? may be like secondary mirroring display mode. How to config /etc/X11/xorg.conf properly?

So that I can use the desktop no matter real monitor has connected to HDMI port or not.

scalopus
  • 333

1 Answers1

0

Main problem here is that the KMS (Kernel Mode Setting) is on in modern kernels. This needs to be disabled by creating rules to modprobe depending your card:

For ATI graphics:

echo options radeon modeset=0 > /etc/modprobe.d/radeon-kms.conf

For Intel graphics:

echo options i915 modeset=0 > /etc/modprobe.d/i915-kms.conf

For Nvidia i suggest blacklisting nouveau driver and use vesa on xorg.conf

Now if your modeline is setted correctly you should be able to connect your monitor on the fly.

Pasi Suominen
  • 1,004