If disabling sync-to-vblank solves your problems then that means the driver is reporting that it "can do" sync to vblank, but then breaking its promise and not doing it when asked. But I'm not sure compiz is doing everything it can to detect such driver behaviour, so won't call it a driver bug just yet.
If disabling sync-to-vblank solves your problems then that means the driver is reporting that it "can do" sync to vblank, but then breaking its promise and not doing it when asked. But I'm not sure compiz is doing everything it can to detect such driver behaviour, so won't call it a driver bug just yet.