Hello!
VGACON disables amdgpu kernel modesetting.
There you have your answer!
There are two sets of
drivers that are overlapped: the installed drivers and the kernel drivers.
It looks like Radeon is directly supported through kernel and you need to take a different approach on the installation process.
Read the manual for proprietary drivers and installing Linux without this kind of drivers. Actually, without any drivers since it is supported "out of the box".
A different approach.If you manage to boot into the normal mode, go to "
Additional Drivers" or use CLI:
/usr/bin/software-properties-gtk --open-tab=4
See what proprietary drivers are installed and uninstall them, or, if this is the case and
you are sure you want to test, install the AMD drivers.Maybe the kernel drivers are unappropriate for your specific version of video GPU.
Another choice is to uninstall any Radeon driver you find installed, using
Synaptic Package Manager.
Good luck!