06-27-2021, 07:50 PM
Ok I'm getting closer. I think the problem is with the linux kernel, specifically the option CONFIG_ROCKCHIP_CDN_DP=y is set on the Debian 5.10.40 kernel. This may cause issues, as I have found a couple of references (https://www.kulesz.me/post/150_devuan_pinebookpro/) to recompiling a kernel without this option and it fixes the display. Curiously, the working Manjaro image runs 5.12 with this option set to yes, so I'm wondering if it's fixed in the latest stable kernel.
I'm going to try recompiling 5.10.40 with that option unset and see if it fixes it, and then I'll try building the latest 5.12 with that option set to yes/defaulted. With this done, all that's left is to get the wifi firmware included into somehow (linux-firmware-nonfree?). You'll need to use u-boot in experimental or grab the itb/u-boot.img/dtbs from the Manjaro image.
I'm going to try recompiling 5.10.40 with that option unset and see if it fixes it, and then I'll try building the latest 5.12 with that option set to yes/defaulted. With this done, all that's left is to get the wifi firmware included into somehow (linux-firmware-nonfree?). You'll need to use u-boot in experimental or grab the itb/u-boot.img/dtbs from the Manjaro image.