linux-toradex.git/kernel/power/autosleep.c, branch v4.9.97 Linux kernel for Apalis and Colibri modules PM / Sleep: avoid 'autosleep' in shutdown progress 2013-07-14T23:31:37+00:00 Liu ShuoX shuox.liu@intel.com 2013-07-11T08:03:45+00:00 e5248a111bf4048a9f3fab1a9c94c4630a10592a 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> 
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>
PM: don't use [delayed_]work_pending() 2013-01-25T23:39:11+00:00 Tejun Heo tj@kernel.org 2013-01-11T12:37:33+00:00 ed1ac6e91a3ff7c561008ba57747cd6cbc49385e 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> 
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>
PM / Sleep: Add "prevent autosleep time" statistics to wakeup sources 2012-05-01T19:25:49+00:00 Rafael J. Wysocki rjw@sisk.pl 2012-04-29T20:53:32+00:00 55850945e872531644f31fefd217d61dd15dcab8 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> 
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>
PM / Sleep: Implement opportunistic sleep, v2 2012-05-01T19:25:38+00:00 Rafael J. Wysocki rjw@sisk.pl 2012-04-29T20:53:22+00:00 7483b4a4d9abf9dcf1ffe6e805ead2847ec3264e 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> 
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>