This reapplies commit acf4e84d.
With async unpin this should no longer break.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463490484-19540-20-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NPatrik Jakobsson <patrik.jakobsson@linux.intel.com>