When I installed Freya on a 22" Screen, everything was fine. But when I plug the PC in a 40" TV, the desktop is upscaled to 200%. The screen resolution is correctly 1920x1080 but because of the upscaling it looks more like 960x540.
When I rescale it with
xrandr --output DFP2 --scale 2x2 the screen looks fine, but the mouse cursor is confined to the top left quarter of the screen.
How can I fix this problem?