(In reply to Carlo Caione from comment #8)
> On a side note: is it normal so many error messages in the journal? Like:
> 
> kernel: amdgpu 0000:00:01.0: ffff9cccade4d800 pin failed
> kernel: [drm:amdgpu_crtc_page_flip_target [amdgpu]] *ERROR* failed to pin
> new abo buffer before flip
> gdm-Xorg-:0[672]: (WW) AMDGPU(0): flip queue failed: Cannot allocate memory
> gdm-Xorg-:0[672]: (WW) AMDGPU(0): Page flip failed: Cannot allocate memory
> gdm-Xorg-:0[672]: (EE) AMDGPU(0): present flip failed
> ...
> gdm-Xorg-:0[672]: (WW) AMDGPU(0): get vblank counter failed: Invalid argument

I think all of these are triggered by VRAM being too small to fit the scanout
buffers covering the laptop panel + external monitor.

> kernel: amdgpu: [powerplay] min_core_set_clock not set

Not sure about this one, might be harmless.