How to set Full range RGB ?

Hi,

I could switch to RGB @Odroid C2 by issuing

echo 'rgb,10bit' > /sys/class/amhdmitx/amhdmitx0/attr

hdmitx: video: Bit depth: 10-bit, Colour range RGB: limited, YCC: limited, Colourspace: RGB

How I could set Full range RGB for Odroids GPU?

I tested also

echo "full,rgb,10bit" > /sys/devices/virtual/amhdmitx/amhdmitx0/attr

got

[1508[email protected]] hdmitx: video: Bit depth: 10-bit, Colour range RGB: full, YCC: full, Colourspace: RGB

But test results are the same, TV detects signal as Full, but colours are washed out and when manually switched to the Limited Range (on TV), picture is OK . So it seems I still get Limited video range, despite hdmitx message