Use msleep instead of tsleep to drop the DRM device lock and avoid a

sleep-with- mutex held. This probably ought to be an os-independent
    sleep function ala DRM_USLEEP.

shared-core/radeon_cp.c

@@ -1701,8 +1701,13 @@ void radeon_do_release(drm_device_t * dev)
 				DRM_DEBUG("radeon_do_cp_idle %d\n", ret);
 #ifdef __linux__
 				schedule();
+#else
+#if defined(__FreeBSD__) && __FreeBSD_version > 500000
+				msleep(&ret, &dev->dev_lock, PZERO, "rdnrel",
+				       1);
 #else
 				tsleep(&ret, PZERO, "rdnrel", 1);
+#endif
 #endif
 			}
 			radeon_do_cp_stop(dev_priv);