OK, one less problem now. For the original BT issue, I'm building again the kernel from the latest stable branch with the revert of the suggested patch. It's being built in OBS home:tiwai:bsc1187472-2 repo. Let's see whether this improves or not. In anyway, the problem has to be resolved in the upstream side. Could you report or follow to the existing upstream ML thread or bug entry after checking the patch revert?