I'm noticing that the default screen brightness of my desktop =
when logged in is
set to something beneath "1" when set to "1" with amdgp=
u.dc=3D1 switch in the
kernel.
Test to get to this point:
* boot PC - (Grub screen brightness is "normal")
* Set kernel value amdgpu.dc=3D1 and proceed with 4.16.0+ kernel boot - (ke=
rnel
switches quiet and splash removed, brightness appears normal during boot
process)
* Lightdm display manager starts (brightness is still "normal")
* Log in to any window manager, When X starts, the desktop is immediately
darkened with what appears to be a high contrast setting. Looks like equiva=
lent
to manual setting I can't actually discern. It's not brightness, necessaril=
y,
but the net effect on the desktop is that everything is effectively darker.
* I've tested this with Ubuntu's Unity desktop, and gnome-flashback (compiz=
and
metacity), and it behaves the same.
When amdgpu.dc=3D0 is set, desktop appears a normal level of brightness when
logging in. It appears from the Xorg.0.log that the AMDGPU module isn't used
for X, but brightness isn't affected.
I'll include logs from amdgpu.dc=3D0 and amdgpu.dc=3D1. Let me know if you =
need any
other logs.