https://bugzilla.kernel.org/show_bug.cgi?id=199319
--- Comment #4 from Ed Tomlinson (edt@aei.ca) --- I checked my X conf, no tearfree option is set, using 4.15 I set tearing prevention to never and rebooted into 4.16.1-rc.
This does NOT stop the flickering here.
Flicking does not occur with 4.15 dc-1 and does with 4.16.
IMO this is a regression.