Prevent automatic system suspend from happening during system
shutdown by making try_to_suspend() check system_state and return
immediately if it is not SYSTEM_RUNNING.
This prevents the following breakage from happening (scenario from
Zhang Yanmin):
Kernel starts shutdown and calls all device driver's shutdown
callback. When a driver's shutdown is called, the last wakelock is
released and suspend-to-ram starts. However, as some driver's shut
down callbacks already shut down devices and disabled runtime pm,
the suspend-to-ram calls driver's suspend callback without noticing
that device is already off and causes crash.
[rjw: Changelog]
Signed-off-by: Liu ShuoX <shuox.liu@intel.com>
Cc: 3.5+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There's no need to test whether a (delayed) work item is pending
before queueing, flushing or cancelling it, so remove work_pending()
tests used in those cases.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Android uses one wakelock statistics that is only necessary for
opportunistic sleep. Namely, the prevent_suspend_time field
accumulates the total time the given wakelock has been locked
while "automatic suspend" was enabled. Add an analogous field,
prevent_sleep_time, to wakeup sources and make it behave in a similar
way.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce a mechanism by which the kernel can trigger global
transitions to a sleep state chosen by user space if there are no
active wakeup sources.
It consists of a new sysfs attribute, /sys/power/autosleep, that
can be written one of the strings returned by reads from
/sys/power/state, an ordered workqueue and a work item carrying out
the "suspend" operations. If a string representing the system's
sleep state is written to /sys/power/autosleep, the work item
triggering transitions to that state is queued up and it requeues
itself after every execution until user space writes "off" to
/sys/power/autosleep.
That work item enables the detection of wakeup events using the
functions already defined in drivers/base/power/wakeup.c (with one
small modification) and calls either pm_suspend(), or hibernate() to
put the system into a sleep state. If a wakeup event is reported
while the transition is in progress, it will abort the transition and
the "system suspend" work item will be queued up again.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Liu ShuoX
Tejun Heo
Rafael J. Wysocki