https://bugzilla.kernel.org/show_bug.cgi?id=212449
--- Comment #2 from Vyacheslav Dikonov (sdiconov@mail.ru) --- I doubt that. Please, see my ddccontrol logs with different settings. It shows that ddccontrol cannot access the controls unless the options are set as dc=0, hw_itc=0. All logs are taken under root and with POSIX locale. I also add a reference log drom a different machine attached to the same display.