Extreme backlight leak when using AMDGPU

[arnav7633]

Hey all! Whenever i try to use amdgpu irrespecitve if its a distribution kernel or a custom built one extreme amounts of backlight leak and my display managers like ssdm even fail to start the problem disappears if using the default radeon driver
http://dpaste.com/AX446B7UB <<< Journal
http://dpaste.com/7APHZNQNC <<<dmesg

Here is what my display looks like
https://ibb.co/VJpTGPf
If you see closely you can see i got into tty

[Goverp]

There's a bug in very recent kernels where the amdgpu driver tries to use a 16 bit brightness in a field defined only for 8 bits - or something like that. IIUC it's fixed in a later version of the kernel. That said, the symptoms for me were just very bright text, not a white screen, so this might not be the same issue.

For me, the cure is to use a lower value, such as 128, into the appropriate /sys control - the example below is for my setup, the <amdgpu> bit is board-dependent. Your system might have a /proc control for brightness, depending on kernel configuration.