Comment 12 for bug 289177

I have a similar problem with the same video chipset. If I start X with VGA connected but not HDMI, everything works fine (except that I would rather not use VGA). If I start X with HDMI connected but not VGA, then I get nothing. The monitor doesn't even get a signal. If I use the radeonhd driver instead of radeon, HDMI works. Also, fglrx works fine under Ubuntu. So, this would appear to be a bug in the radeon driver. In my case, the HDMI connection is a HDMI-to-DVI cable connected to the DVI port of my monitor. I will attach my X logs to this bug.