I'm not sure it's regression issue or not, but it's also happen on 3.19 kernel ( 3.19.0-27 ) "with" HDMI plug, if I unplug the HDMI and test it again then the system can be shutdown without hang.
so the different between original kernel and bpo 2.2 is : bpo 2.2 encounter shutdown hang "without" HDMI plug
and both encounter this issue "with" HDMI plug.
I'm not sure it's regression issue or not, but it's also happen on 3.19 kernel ( 3.19.0-27 ) "with" HDMI plug, if I unplug the HDMI and test it again then the system can be shutdown without hang.
so the different between original kernel and bpo 2.2 is : bpo 2.2 encounter shutdown hang "without" HDMI plug
and both encounter this issue "with" HDMI plug.