4K resolution monitor interface with Jetson Nano

Hello,

I build custom carrier board for Nvidia Jetson Nano SOM.
In this I have got one issue.
When I connect new 4K resolution monitor to the board or I flash the SOM and connect to 4K resolution monitor in both cases only initial NVIDIA boot screen appear and after that screen goes blank.
After manual setting when I select 1080p resolution then display output is observed.
After working on this issue I found out that due to there is some issue with my custom carrier board Nano can able to work with 4K resolution HDMI output with maximum 30 FPS only. This condition is same for DP port also.
Now I just want to know that Is there any way when SOM connect to any new 4K resolution display instead of selecting maximum mode of 3840x2160 @ 60 FPS it should select 3840x2160 @30FPS?
Is there any way we can restrict Display mode selection to maximum 3840x2160 @30FPS?
Please guide me on this.
Thanks.

You should not use Jetson Nano for new development. Nano is based on TX1 and End of Life. Software support is long over. You should use Orin Nano for new products.

Hello,

Thanks a lot for reply.
Definately I think on this suggestion.
Our custom carrier board is designed for multiple type of SOM like Nano and Xavier NX.
But right now display issue is coming for all the SOMs.
For reference purpose I took Nano SOM. If the things work on it definately I will try to implement on other SOM.
Please guide me on this Monitor resolution setup.
Thanks.

One comment seems not true to me…

But right now display issue is coming for all the SOM

TX1/Nano cannot support that resolution from its nature… but this is not true for Xaiver or Orin NX…

Hello,

Thanks a lot for reply.

I think in all the SOMs Display driver functionality is same.
Ideally when I connect new 4K monitor first time SOM read its EDID and commonly select highest resolution and frame rate.
Most of 4K display has maximum 3840x2160 resolution and 60 fps.
In our carrier board unfortunately its observed that for 3840 x 2160 resolution max fps range for proper functionality is upto 30 fps only.
Because of this every time when I connect new 4K monitor to our carrier board display is not coming.
To resolve this issue I was trying to restrict fps to 30 only.
I check few other links on forum in that they suggest to add node in xorg.conf.
But there I found setting for resolution only not for frame rate.
Please guide me on this issue.

Thanks.

Of course they are not same… Why is different generation of SoC doing here? You think the chip released in 6~7 years ago have same performance as chips nowadays?

Hello,

Ok I will take reference of Nano SOM only.
For time being will try to resolve this issue for Nano only.
Using xrandr command I can manually choose resolution and fps for attached display but its not perment.
After reboot again SOM take maximum configuration.
Is there any way we can do some device tree changes and make the som to support max 30 fps at 4K resolution?

Thanks.

Could you share the result of xrandr from your board first?

Hello,

Sorry for delayed reply.

Please check below image


I have flashed Nano SOM and after setting I connect this som to new two 4K monitors.
Here I am not getting display (no HDMI /no DP).
I took access of SOM through serial port and I run xrandr command.
By default SOM select maximum resolution 3840x2160 and 60FPS.
I want to restrict it to 30 FPS.

Thanks.

please try How to fixed HDMI resolution output 1920x1080p - #4 by WayneWWW

Hello WayneWWW,

Thanks for link.
Its really helpful.
I checked this link.
By default in config folder not having any monitors.xml file. When we do any display setting that time unity-monitors.xml file is created.
In this unity-monitors.xml file I tried to add possible combination of HDMI and DP monitors resolutions.
unity-monitors.xml.txt (8.1 KB)
Now when system boot SOM consider maximum configuration of 3840 x 2160 30fps for 4K monitors.
Now I am getting one issue that suppose if I connect only HDMI display then it works fine, but when I connect only DP display then I am not getting DP display.

Also I had one doubt that this Will this unity-monitors.xml file should applicable to other 4K , 1080p and 720p monitors?
Please guide me on this.
Thanks a lot for support.

Thanks.