Maybe not Rock Pi related in particular, but still curious if anybody ever had same experience and/or knows how to resolve that.
Up to now I used the HDMI cable for connecting Rock 5B to my DELL U2711 monitor. This old monitor doesn’t natively support higher resolution than 1920x1080 on the HDMI connection. Using the modeline setting I was able to resolve that and to get the full native resolution of 2560x1440 working under X11. But I decided to switch to Wayland now. Unfortunately for Wayland it seems there is no possible solution for SBC not using Grub yet.
So I decided to use the HDMI to DVI cable I had and used earlier for PC. I booted the Rock from SD card and viola it works, full QHD resolution in Wayland! But when I change the SD for another one with another working image or remove it and let the Rock to boot from emmc, it doesn’t send the video signal to monitor any more. The screen is black and the monitor suspends. But the system is up, I can log in via SSH. If I add HDMI to HDMI connection from the second HDMI port in the Rock to the HDMI port in the monitor, I can get the screen working after switching the monitor input to the HDMI port. System correctly recognizes that two displays are connected (even though in one monitor) and provides the extending or copying the workspace to the second screen. But the second one on the HDMI to DVI connection is still without the signal.
When I plug in the “correct” SD card back, the HDMI to DVI connection is working again. I really don’t understand what the hell is going on…
Any idea out there?