I just purchased a hyperpixel 4 and am having issues getting it working. I have tried on a Pi 3 B, Pi 3 B+ and a Pi 4, and am having the same issues, so I suspect hardware. I tried the built in driver in both Bookworm and Bullseye, and enabled via dtoverlay=vc4-kms-dpi-hyperpixel4 in the config.txt. I verified i2c was disabled as well. The issue is the screen display the image, but there is a constant scrolling down. Almost like a refresh issue on a CRT. I spent a few hours searching and have not seen any posts or questions describing the same issue, so I thought I would ask here. Any suggestions, or am I looking at a suspected hardware issue?
Of course after posting my question I found a similar issue. This thread is a very similar issue. I also get the ghosting when powering off and powering on the Pi(last image is retained on screen).
I resolved this “issue” on my own. Apparently I can’t follow directions. I added the line in the config.txt to support the rectangle hyperpixel, and not the square. I still have noticeable ghosting(image burn in) and flicker, but I think I can work around that.
Once installed you need only one line in /boot/config.txt:
After using the display for 30 minute or so the ghosting and flickering has resolved on it’s own. This display is awesome, and have tons of ideas for how to use these at work.