It appears the regression was introduced in v3.16.7-ckt1. Can you also see if v3.16.7-ckt2 exhibits this bug? It can be downloaded from:
http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.16.7-ckt2-utopic/
It appears the regression was introduced in v3.16.7-ckt1. Can you also see if v3.16.7-ckt2 exhibits this bug? It can be downloaded from:
http:// kernel. ubuntu. com/~kernel- ppa/mainline/ v3.16.7- ckt2-utopic/