@Peter,
Please take a look at https://askubuntu.com/questions/1032811/ubuntu-18-04-no-hdmi-audio-with-amd-radeon-hd-7870/1207919#1207919
Now the driver amdgpu and nouveau(dispnv50) support the audio_component, but the driver radeon doesn't support it yet. so please try the workaround in the askubuntu.com or please read #53
@Peter,
Please take a look at https:/ /askubuntu. com/questions/ 1032811/ ubuntu- 18-04-no- hdmi-audio- with-amd- radeon- hd-7870/ 1207919# 1207919
Now the driver amdgpu and nouveau(dispnv50) support the audio_component, but the driver radeon doesn't support it yet. so please try the workaround in the askubuntu.com or please read #53