Answer to "Flickering screen on low back light"I had the same issue after upgrading to Android 5. Disabling HW overlay worked until recently on Android 6. My current solution is to always use rootdim to adjust the brightness and never lower the brightness below 30. If you need to lower the brightness further then use Kernel Adiutor and adjust the screen colour. Yes, this will need you to root your device. Or use a screen filter app. I forgot to mention that you'll also need to run an app that fixes screen burn-in with the brightness switched to maximum for maybe 9 hours before using Rootdim.