The MUSB driver does not allow CORE RET/OFF to be achieved, even when a USB
cable is not connected.
Bug present in omapzoom master as of today.
Steps to reproduce:
Boot a kernel with MUSB built-in. Enable PM counters
(echo 1 > /sys/power/enable_debug)
After sufficient inactivity, check the counters
CORE RET and CORE OFF counts will be zero.