The problem of display in DP interface

I designed a carrier board for TX1. I use DP interface for display but it do not work. The schematic is refer to the document:JetsonTX1_OEM_Product_DesignGuide page 39. The problem is that when I used a DP-to-DP cable to connect a DP monitor,the monitor display nothing,whenever hot plug or no hot plug. When I used a DP-to-HDMI cable to connect a HDMI monitor,the monitor display nothing when no hot plug,but it display well when hot plug after the TX1 power up.The TX1 that I used is the one in TX1 Developer Kit that use HDMI interface,so I doubt that whether the TX1 configuration would be modified when I use DP interface in my carrier board.

What is the output of this for both the DP and HDMI variants you are testing:

sudo -s
cat `find /sys -name 'edid'`


Have you found the cause and fixed the problem?
Any good result to share or need further assistance?


I have found the cause.Because I found the jachen’s answer of the question: There are some other software changes to bring-up DP1.
But I didn’t try this way because that monitor is a debug way in my project and the time limit of my project is closing.So our software engineer focused on other things.For debuging monitor,I pulled the TX1’s pin “DP1_HPD” to GND and used a DP-to-HDMI cable to connect a HDMI monitor.The monitor would display although having a problem.The problem is that the monitor’s resolution will stay in 800x600 in the beginning of system startup,after about 3 minutes,the resolution will change to the best status automatically.
I will try to change the software as jachen’s answer when our software engineer’s other work done.Then I will reply again.