In nvme_ctrlr_hw_reset(), if we encounter a controller whose CC.EN bit
is already 0 (controller is disabled), the previous code would enable
the controller just so that it could be disabled to get a full reset
(transition from CC.EN = 1 to CC.EN = 0). However, it is a safe
assumption that if CC.EN is already 0, the controller has just been
reset, so we don't need to reset it again.
This saves a significant amount of time (2+ seconds per controller with
Intel SSD DC P3700) during initialization for devices that were disabled
on startup.
Change-Id: I552b1f0f185a84a8a0ce57a93b012d9d5fe096f3
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
a15573c47c