PM: Add watchdog to catch lockup during device resume

Refactor the dpm suspend watchdog code and add watchdogs
on resume too. The dpm wachdog prints the stack trace and
reboots the system if a device takes more than 12 seconds
to suspend or resume.

Change-Id: If00c047a17b80bdc13a8426393c698bc450a7347
Signed-off-by: Benoit Goby <benoit@android.com>
PM / Sleep: Look for wakeup events in later stages of device suspend

Currently, the device suspend code in drivers/base/power/main.c
only checks if there have been any wakeup events, and therefore the
ongoing system transition to a sleep state should be aborted, during
the first (i.e. "suspend") device suspend phase.  However, wakeup
events may be reported later as well, so it's reasonable to look for
them in the in the subsequent (i.e. "late suspend" and "suspend
noirq") phases.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PM / QoS: Create device constraints objects on notifier registration

The current behavior of dev_pm_qos_add_notifier() makes device PM QoS
notifiers less than useful.  Namely, it silently returns success when
called before any PM QoS constraints are added for the device, so the
caller will assume that the notifier has been registered, but when
someone actually adds some nontrivial constraints for the device
eventually, the previous callers of dev_pm_qos_add_notifier()
will not know about that and their notifier routines will not be
executed (contrary to their expectations).

To address this problem make dev_pm_qos_add_notifier() create the
constraints object for the device if it is not present when the
routine is called.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by : markgross <markgross@thegnar.org>