Initially filed downstream on Fedora 20: https://bugzilla.redhat.com/show_bug.cgi?id=1097045
See that bug report for details, systemd journal logs, etc.
journalctl output: https://bugzilla.redhat.com/attachment.cgi?id=894972
Since kernel 3.14 on Fedora 20, I can't suspend my desktop computer anymore. The suspend/resume operation "seems to work" generally speaking, but it borks the state of the graphics driver. This used to work fine in kernel 3.12 (and I think 3.13 too).
Symptoms: extremely sluggish operations for anything that involves 3D (ex: gnome shell animations). This persists until a complete reboot (reloading gnome shell, or using "systemctl isolate multi-user.target && systemctl isolate graphical.target" doesn't solve it).
The journalctl output seems to indicate that the radeon driver is freaking out about UVD, among other things:
> [drm:uvd_v1_0_start] *ERROR* UVD not responding, trying to reset the VCPU!!!
> [drm:uvd_v1_0_start] *ERROR* UVD not responding, giving up!!!
> [drm:si_startup] *ERROR* radeon: failed initializing UVD (-1).
Does it work properly with 3.15? There were some suspend and resume fixes in 3.15 that should make their way back to stable kernels. If not, can you bisect?