Feature introduces problems
I have connected eDP display to my rk3399 board, it works amazingly with every kernel, but I noticed some things when I was using DRM Rendering API through Xorg, I found out with the oscilloscope by probing eDP signals that, when I use linux kernel 4.4, the data what I have sent is perfect but when I use linux 4.19, 5.10 or 6.1, they are doing some manipulation over the the data. In higher versions of kernel my data byte for each channel gets subtracted by 1 in random order.
I am using RGB888 format across the kernels, I tried vendor kernel as well as mainline kernel, still I have not found why this is happening. I tried to find the cause of this, by git commit history but there was no luck either. I don’t have analyzer for HDMI signals actually and I don’t want to make it by self as well due to time constraints, but I am not suspecting the Hard IP changes much, I think there is a somewhat change in the VOP buffer itself, I cannot find out the problem or feature there as well, I tried changing planes, removing newly added features and much more, but still no luck.
I will highly appreciate if someone can help me out with this.