How to enable the edp port of TK1?

I design a custom board with TK1,and I want to used the edp port of TK1 to connect to a edp lcd. (2 lane edp)

Only the backlight is powered on,but no any image shown on the lcd.

THe HDMI works well.

Is there any software changes needed? The default display output is HDMI ,not edp?

Thank you for your help

Hi. Try reading this thread