Tried with radeon.dpm=0 on current mainline - no difference, still got the
stuck message and delayed resume. Also tried with 3.8 Ubuntu stock kernel and
3.10.1 kernel from Ubunty daily mainline builds - the issue doesn't exist on
both kernels. So it matches my vague memory that it started post 3.11 - unsure
if that was after dpm or some other patchset prior to that.