Read 4K display size?

[ycshin]

Hello,

I set the SOM-RK3399 with UHD (3840x2160) display.
and changed display resolution to 3840x2160p60.

It works well as 4K display.

but I can't detect display size 3840x2160.


read size only 1920x1080.

How can I correct this?
I need the real 4K display size.

[ycshin]

Hi, have you found a solution?

NO, I heard that kernel should be modified.
Which files should be changed?