Created attachment 91796 [details]
dmesg output (UVD lockup with dpm off)

I can confirm that with dpm disabled, the problem persists.

One interesting thing that occurred with dpm off, which didn't happen with it
on, is that while repeatedly closing and opening a file for testing, at one
point UVD appears to have totally locked up, seemingly requiring a reboot. The
lockup persisted when closing and restarting X. Attached is the output in dmesg
from when that happened.