I've got a Samsung laptop (archey reports "AMD E-450 APU with Radeon(tm) HD Graphics") from ca. 2010 that I'm essentially using mainly to run Kodi/XBMC hooked up to a TV via HDMI, running with Manjaro (Arch-base), using Xfce as my DE.

I am running with the Radeon video drivers, and just want video/sound output to appear on the TV (no laptop display), at least while the HDMI is plugged in.

The trouble I run into is this: whenever I turn off the TV, or change the TV source to something other than the HDMI port the laptop is plugged into, then the laptop screen comes back on, and even when I switch the TV back on, the display is messed up, and I have to pull up Display, and turn the laptop screen back off, and then quickly Alt-Tab to get to the confirmation of Display setting change dialogue up and confirm it.

Is there any way to fix it so that when HDMI is plugged in, it automatically turns off the laptop screen, so that the display doesn't get messed up in this way?

Or other suggestions on a fix or work-around?

You could try using the udev and a script (using xrandr) to automatically detect/configure the display outputs according to the external monitor connection status.

For example

http://ruedigergad.com/2012/01/28/ho...ptop-on-linux/

Post #7 of this thread

https://bbs.archlinux.org/viewtopic.php?id=170294

Hopefully, that is enough to get you started and customize as you'd like.

Your laptop should have a monitor key that's used in conjunction with an fn-key, use the key to properly disconnect before disconnecting & after connecting should be the solution to your problem.