tags 969287 + moreinfo,help thanks Hello,
I am sorry for not answering to this bug report sooner; I cannot test to reproduce what you say (I have only one MicroHDMI cable), and even if I could, I really don't think I can do much to help. Your bug report has a lot of interesting insight, but I will not say I am the best equipped to make sense out of it. The situation has evolved quite a bit since you filed the bug, and having both newer firmware and kernel versions, I wouldn't be surprised if this issue managed to fix itself. I understand (but don't know for sure) advances have been made regarding vc4 support in mainline Linux. So, do you still have this behavior? Have you (or has anybody else) been able to get dual-screen support on your RPi4? Or do you have any promising pointers on this? Thanks,