4K 60hz over HDMI or DP


#1

Has anyone gotten 4K 60 hz video to work on their Rock960? I’ve only gotten it to display up to 1440p 60 hz over HDMI and haven’t had any luck getting DP over USB-C to output a signal.
I tried the default Android image it came with, Ubuntu 16.04, 18.04 aarch64 images, and Debian armhf images but all of them seem to have the same video mode limitations.


#2

Hi,

what’s the output of

cat /sys/class/drm/card0-HDMI-A-1/mode

after you plugin HDMI to a 4K TV.


#3

I get
2560x1440p60
after plugging it in to a 4K monitor. I have verified that the HDMI cables I am using support 4K as I have used them with my workstation.


#4

Sorry, I mean the modes, to show all the resolutions.

cat /sys/class/drm/card0-HDMI-A-1/modes

#5

All the modes I get are:
2560x1440p60
1920x1080p60
1920x1080i60
1600x900p60
1280x1024p60
1152x864p60
1280x720p60
1024x768p60
800x600p60


#6

The HDMI resolution should be right. I think I misunderstand your issue, you are using type C to DP adapter, right? Currently, both Android and Ubuntu should support type C display output. We have tested with type C to HDMI adapter. If it doesn’t work for you try to plug and reserve plug the type C port. Also, can you post the dmesg after you plug in the type C port?


#7

Sorry I didn’t clarify. I’m having two separate issues, one with the HDMI connection not supporting 3840x2160p60 for my 4K monitor, and the other is I can’t get a DP signal with a USB-C to DP adapter with the same monitor. I’m using this adapter:


I’m using this LG 4K monitor:

Thanks,