I just completed my first mainline driver!
My goal was to enable night light on OnePlus 6 using #phosh on #postmarketos.
It was a missing DRM GAMMA_LUT support in the Qualcomm Display Engine (DPU) driver.
I used the downstream kernel as a reference and found the LUT format by trial and error on the phone.
It was a difficult but very rewarding experience.
I pushed the code here https://gitlab.com/sdm845-mainline/linux/-/merge_requests/137#note_2807562800