https://bugs.freedesktop.org/show_bug.cgi?id=106228
--- Comment #2 from Harry Wentland harry.wentland@amd.com --- That patch only affects Carrizo and should only be needed for S3.
We don't see this issue with Ubuntu 18.04 on a Raven laptop we have available. The OS (Gnome) shows brightness as expected on boot.
I wonder if some laptops behave differently but I can't think why.