I'm running Lubuntu 14.10 with a AMD 5350 with Radeon R3 in my living room connected to my TV via HDMI. As long as my TV was on when the system is booted everything is fine (audio and video). However if I turn the TV and leave it off, the next time I turn it on, the bottom half of the display gets distorted. I tried switching to the proprietary ATI driver but that didn't help this problem. The top half is still the correct resolution but just the bottom half is messed up. The only way to get the screen correct again, that my limited knowledge knows, is to reboot the system. I'm assuming the problem has to do with the computer recognizing that there is no connection on the HDMI when the TV is turned off but not readjusting when the TV is turned back on.
Ideally, there'd be a setting to have the computer ignore when the TV is turned off and never change the display as a result of the TV being turned off.
If that can't be achieved, is there a way I can reset the video without restarting the whole system from the command line (or a script)?
There are two different fixes that I've found.
If I
sudo apt-get install fglxrinstead of just relying on the the Additional Drivers gui then it seems to work.This method has the downside of VDPAU not working. It complains of a missing nvidia file which is obviously a contradiction as it's an AMD card.
If I use the OS driver the vdpau works but the screen does the weird distortion thing after it has been power cycled. Instead of rebooting the computer I can run
DISPLAY=:0 xrandr -qto see the device name of my TV then runto reset the display. With that command I can make a script which I can map to a hotkey which I can map to my remote to make the glitch essentially non-existent.
The second solution was courtesy of this post on forum.kodi.tv.
There was a third (actually first but it didn't work) solution proposed of saving the firmware edid (I'm probably not using one or both of those terms correctly) to a file and forcing its continued use which, for me, didn't work.