Hi numbqq
thank you for sharing. I’ve just tried a mainline kernel built upon this config (I assume you are using the meson-gxl-s905x-khadas-vim.dtb), but I still experience these strange network issues. You may try it by yourself by cloning the Linux source code repository via git, e.g.
git clone --depth 1 --single-branch -b master https://github.com/ioft/linux/
If the download stalls, a simple ifdown / ifup eth0 (via serial console) will get the network connection operational again.
Cheers
Uli