Fixing vop problem with linux 4.19 of rockchip

Edge
1

I am currently using Ubuntu, with community builds.

Linux Specific Issue

I want to capture streaming data from the one Edge-V and store it onto other.
I have built custom linux kernel from the official rockchip repos, I am using a type-C port as DisplayPort, and from that port I have connected to bridge which is of LT7911D, which converts that to MIPI, So the bridge becomes my second display and I am screen mirroring to do stream cap, I am able to do this precisely with the linux-4.4 provided by rockchip, then I have tried the same thing with the linux-4.19 but the problem is, some random bytes from the display is getting corrupted, it gets subtracted by 1 in many pixels, the problem arises with linux-4.19 only, I am using DP on vopb and my other HDMI monitor on vopl in both kernels, and I am using RGB888 format to send the data.

One thing I have noticed is, whenever my any color channel value goes below 64 it gets subtracted by 1. I am using this GitHub - dvdhrm/docs: API Documentations, HowTos and Tutorials user space utility to send fine tuned data.

There might be definitely some feature added in linux-4.19, but I want to remove that feature. Can somebody help?

2

Look for gamma lut :wink:

3

I tried disabling it, it fixed my issue, but what if I don’t want to disable it and just change same gamma lut table, I don’t know from where that is getting written onto the registers, I am still looking into, someone’s help will be more than sufficient for me to continue.