Disable internal display for chipset using i915 driver on Linux

Just found a quick way for disabling internal display on i915.

Using command modinfo i915, there will be an options called panel_ignore_lid.

According its description, panel_ignore_lid:Override lid status (0=autodetect [default], 1=lid open, -1=lid closed) (int).

So create a new file under /etc/modprobe.d name it i915.conf

Adding following:

options i915 panel_ignore_lid=-1

You are done! (Don't forget to reboot)