(In reply to taijian from comment #20)
> OK, here is a new twist: upon further investigating this, I came across some
> weird backlight behaviour that I originally reported here:
> https://gitlab.gnome.org/GNOME/gnome-settings-daemon/issues/53. However, as
> it turns out, this is not a gnome issue but a kernel one.
> 
> Namely, doing 
> 
>   echo X > /sys/class/backlight/intel_backlight/brightness
> 
> will wake my dGPU, even though it really shouldn't be involved at all (and
> does not have a /sys/class/backlight device registered). Furthermore,
> repeatedly invoking this command before the dGPU has had the chance to go
> back to sleep will not do anything. Thirdly, this seems to be a very good
> way to get the system to hard lock up.
> 
> So, is this an amdgpu issue? A i915 issue? ACPI? where should I take this
> bug report?

What do you mean by 'wake' the dGPU? This should be a separate ticket which you
can submit here + attach dmesg after this 'wake'.