https://bugs.freedesktop.org/show_bug.cgi?id=49747
--- Comment #5 from Alex Deucher agd5f@yahoo.com 2012-05-10 11:18:49 PDT --- Is the failure only after a dpms cycle or does the second DP monitor not light up at all? If the former, are there any driver messages in dmesg when after a failed dpms cycle?