Created attachment 111880 [details]
Logs from a reproduction of the bug using recent software

I'm seeing the same issue with Xorg 1.16.2.901, Linux 3.16.0, and a Radeon HD
7750.  I've attached DRM logs that contrast the behavior when the monitor is
power-cycled in X (there's no signal when the monitor is powered back on) to
the behavior when the monitor is power-cycled in kernel framebuffer VT (the
signal returns when the monitor is powered back on), but am not sure what to
make of them.

Thanks!