https://bugs.freedesktop.org/show_bug.cgi?id=88152
--- Comment #6 from Christian König deathsimple@vodafone.de --- (In reply to Arthur Marsh from comment #4)
The commit:
https://github.com/torvalds/linux/commit/ dd5a74f2f982193620cfa1ef609df1ee805781d4
appears to at least reduce the problem.
The patch can't affect the issue, cause it only applies to non UMS mode which is completely deprecated and doesn't support UVD at all.