Arm video tearing

I had an app with lots of video tearing on raspberry3b+ with raspbian 10, of 11.
Vertical sync enabled, 30 & 60fps. Lots of tearing. Then I sudo raspi-config, disable the video compositor, gl driver full dkms, reboot, and tearing is gone. This is not obvious, thought I’d share. Also, apparently Mesa has some issues with these arm drivers, and sometimes I got a harmless Draw call returned invalid argument. Expect corruption.