Shutdown -r for RPI2 hangs on serial console

[bob prohaska]

Hi All,

Last couple of reboots of RPI2 have stuck when issued on
the serial console. Using the same command when su-d to
root over ssh seems to work.

The console shows:

root at www:/usr/src # shutdown -r now
Shutdown NOW!
shutdown: [pid 698]
root at www:/usr/src #                                                                                
*** FINAL System shutdown message from root at www.zefox.com ***             Stopping cron.
Waiting for PIDS: 620.
Stopping sshd.
Waiting for PIDS: 601.
Stopping powerd.
Waiting for PIDS: 562.
Stopping casperd.
Waiting for PIDS: 507.
Stopping devd.
Waiting for PIDS: 335.
Writing entropy file:.
.
Terminated
Apr 14 09:29:55 www syslogd: exiting on signal 15
Waiting (max 60 seconds) for system process `vnlru' to stop...done
Waiting (max 60 seconds) for system process `bufdaemon' to stop...done
Waiting (max 60 seconds) for system process `syncer' to stop...
Syncing disks, vnodes remaining...3 1 1 0 0 done
All buffers synced.
[plug pulled after waiting a few minutes]

During reboot the serial console reports that / wasn't properly dismounted
but the system seems to recover satisfactorily.

Is this something I'm doing wrong? Latest revision to display the 
behavior is r297909.

Thanks for reading,

bob prohaska