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-rw-r--r--Documentation/ABI/testing/sysfs-devices-power18
-rw-r--r--Documentation/power/runtime_pm.txt190
-rw-r--r--drivers/base/power/runtime.c186
-rw-r--r--drivers/base/power/sysfs.c40
-rw-r--r--include/linux/pm.h8
-rw-r--r--include/linux/pm_runtime.h45
6 files changed, 473 insertions, 14 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power
index 6bb2dd3c3a7..7628cd1bc36 100644
--- a/Documentation/ABI/testing/sysfs-devices-power
+++ b/Documentation/ABI/testing/sysfs-devices-power
@@ -147,3 +147,21 @@ Description:
milliseconds. This attribute is read-only. If the device is
not enabled to wake up the system from sleep states, this
attribute is empty.
+
+What: /sys/devices/.../power/autosuspend_delay_ms
+Date: September 2010
+Contact: Alan Stern <stern@rowland.harvard.edu>
+Description:
+ The /sys/devices/.../power/autosuspend_delay_ms attribute
+ contains the autosuspend delay value (in milliseconds). Some
+ drivers do not want their device to suspend as soon as it
+ becomes idle at run time; they want the device to remain
+ inactive for a certain minimum period of time first. That
+ period is called the autosuspend delay. Negative values will
+ prevent the device from being suspended at run time (similar
+ to writing "on" to the power/control attribute). Values >=
+ 1000 will cause the autosuspend timer expiration to be rounded
+ up to the nearest second.
+
+ Not all drivers support this attribute. If it isn't supported,
+ attempts to read or write it will yield I/O errors.
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index 9ba49b21ac8..489e9bacd16 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -158,7 +158,8 @@ rules:
to execute it, the other callbacks will not be executed for the same device.
* A request to execute ->runtime_resume() will cancel any pending or
- scheduled requests to execute the other callbacks for the same device.
+ scheduled requests to execute the other callbacks for the same device,
+ except for scheduled autosuspends.
3. Run-time PM Device Fields
@@ -166,7 +167,7 @@ The following device run-time PM fields are present in 'struct dev_pm_info', as
defined in include/linux/pm.h:
struct timer_list suspend_timer;
- - timer used for scheduling (delayed) suspend request
+ - timer used for scheduling (delayed) suspend and autosuspend requests
unsigned long timer_expires;
- timer expiration time, in jiffies (if this is different from zero, the
@@ -236,6 +237,23 @@ defined in include/linux/pm.h:
Section 8); it may be modified only by the pm_runtime_no_callbacks()
helper function
+ unsigned int use_autosuspend;
+ - indicates that the device's driver supports delayed autosuspend (see
+ Section 9); it may be modified only by the
+ pm_runtime{_dont}_use_autosuspend() helper functions
+
+ unsigned int timer_autosuspends;
+ - indicates that the PM core should attempt to carry out an autosuspend
+ when the timer expires rather than a normal suspend
+
+ int autosuspend_delay;
+ - the delay time (in milliseconds) to be used for autosuspend
+
+ unsigned long last_busy;
+ - the time (in jiffies) when the pm_runtime_mark_last_busy() helper
+ function was last called for this device; used in calculating inactivity
+ periods for autosuspend
+
All of the above fields are members of the 'power' member of 'struct device'.
4. Run-time PM Device Helper Functions
@@ -261,6 +279,12 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
error code on failure, where -EAGAIN or -EBUSY means it is safe to attempt
to suspend the device again in future
+ int pm_runtime_autosuspend(struct device *dev);
+ - same as pm_runtime_suspend() except that the autosuspend delay is taken
+ into account; if pm_runtime_autosuspend_expiration() says the delay has
+ not yet expired then an autosuspend is scheduled for the appropriate time
+ and 0 is returned
+
int pm_runtime_resume(struct device *dev);
- execute the subsystem-level resume callback for the device; returns 0 on
success, 1 if the device's run-time PM status was already 'active' or
@@ -273,6 +297,11 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
device (the request is represented by a work item in pm_wq); returns 0 on
success or error code if the request has not been queued up
+ int pm_request_autosuspend(struct device *dev);
+ - schedule the execution of the subsystem-level suspend callback for the
+ device when the autosuspend delay has expired; if the delay has already
+ expired then the work item is queued up immediately
+
int pm_schedule_suspend(struct device *dev, unsigned int delay);
- schedule the execution of the subsystem-level suspend callback for the
device in future, where 'delay' is the time to wait before queuing up a
@@ -304,12 +333,20 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
- decrement the device's usage counter
int pm_runtime_put(struct device *dev);
- - decrement the device's usage counter, run pm_request_idle(dev) and return
- its result
+ - decrement the device's usage counter; if the result is 0 then run
+ pm_request_idle(dev) and return its result
+
+ int pm_runtime_put_autosuspend(struct device *dev);
+ - decrement the device's usage counter; if the result is 0 then run
+ pm_request_autosuspend(dev) and return its result
int pm_runtime_put_sync(struct device *dev);
- - decrement the device's usage counter, run pm_runtime_idle(dev) and return
- its result
+ - decrement the device's usage counter; if the result is 0 then run
+ pm_runtime_idle(dev) and return its result
+
+ int pm_runtime_put_sync_autosuspend(struct device *dev);
+ - decrement the device's usage counter; if the result is 0 then run
+ pm_runtime_autosuspend(dev) and return its result
void pm_runtime_enable(struct device *dev);
- enable the run-time PM helper functions to run the device bus type's
@@ -360,19 +397,46 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
PM attributes from /sys/devices/.../power (or prevent them from being
added when the device is registered)
+ void pm_runtime_mark_last_busy(struct device *dev);
+ - set the power.last_busy field to the current time
+
+ void pm_runtime_use_autosuspend(struct device *dev);
+ - set the power.use_autosuspend flag, enabling autosuspend delays
+
+ void pm_runtime_dont_use_autosuspend(struct device *dev);
+ - clear the power.use_autosuspend flag, disabling autosuspend delays
+
+ void pm_runtime_set_autosuspend_delay(struct device *dev, int delay);
+ - set the power.autosuspend_delay value to 'delay' (expressed in
+ milliseconds); if 'delay' is negative then run-time suspends are
+ prevented
+
+ unsigned long pm_runtime_autosuspend_expiration(struct device *dev);
+ - calculate the time when the current autosuspend delay period will expire,
+ based on power.last_busy and power.autosuspend_delay; if the delay time
+ is 1000 ms or larger then the expiration time is rounded up to the
+ nearest second; returns 0 if the delay period has already expired or
+ power.use_autosuspend isn't set, otherwise returns the expiration time
+ in jiffies
+
It is safe to execute the following helper functions from interrupt context:
pm_request_idle()
+pm_request_autosuspend()
pm_schedule_suspend()
pm_request_resume()
pm_runtime_get_noresume()
pm_runtime_get()
pm_runtime_put_noidle()
pm_runtime_put()
+pm_runtime_put_autosuspend()
+pm_runtime_enable()
pm_suspend_ignore_children()
pm_runtime_set_active()
pm_runtime_set_suspended()
-pm_runtime_enable()
+pm_runtime_suspended()
+pm_runtime_mark_last_busy()
+pm_runtime_autosuspend_expiration()
5. Run-time PM Initialization, Device Probing and Removal
@@ -561,3 +625,115 @@ As a consequence, the PM core will never directly inform the device's subsystem
or driver about run-time power changes. Instead, the driver for the device's
parent must take responsibility for telling the device's driver when the
parent's power state changes.
+
+9. Autosuspend, or automatically-delayed suspends
+
+Changing a device's power state isn't free; it requires both time and energy.
+A device should be put in a low-power state only when there's some reason to
+think it will remain in that state for a substantial time. A common heuristic
+says that a device which hasn't been used for a while is liable to remain
+unused; following this advice, drivers should not allow devices to be suspended
+at run-time until they have been inactive for some minimum period. Even when
+the heuristic ends up being non-optimal, it will still prevent devices from
+"bouncing" too rapidly between low-power and full-power states.
+
+The term "autosuspend" is an historical remnant. It doesn't mean that the
+device is automatically suspended (the subsystem or driver still has to call
+the appropriate PM routines); rather it means that run-time suspends will
+automatically be delayed until the desired period of inactivity has elapsed.
+
+Inactivity is determined based on the power.last_busy field. Drivers should
+call pm_runtime_mark_last_busy() to update this field after carrying out I/O,
+typically just before calling pm_runtime_put_autosuspend(). The desired length
+of the inactivity period is a matter of policy. Subsystems can set this length
+initially by calling pm_runtime_set_autosuspend_delay(), but after device
+registration the length should be controlled by user space, using the
+/sys/devices/.../power/autosuspend_delay_ms attribute.
+
+In order to use autosuspend, subsystems or drivers must call
+pm_runtime_use_autosuspend() (preferably before registering the device), and
+thereafter they should use the various *_autosuspend() helper functions instead
+of the non-autosuspend counterparts:
+
+ Instead of: pm_runtime_suspend use: pm_runtime_autosuspend;
+ Instead of: pm_schedule_suspend use: pm_request_autosuspend;
+ Instead of: pm_runtime_put use: pm_runtime_put_autosuspend;
+ Instead of: pm_runtime_put_sync use: pm_runtime_put_sync_autosuspend.
+
+Drivers may also continue to use the non-autosuspend helper functions; they
+will behave normally, not taking the autosuspend delay into account.
+Similarly, if the power.use_autosuspend field isn't set then the autosuspend
+helper functions will behave just like the non-autosuspend counterparts.
+
+The implementation is well suited for asynchronous use in interrupt contexts.
+However such use inevitably involves races, because the PM core can't
+synchronize ->runtime_suspend() callbacks with the arrival of I/O requests.
+This synchronization must be handled by the driver, using its private lock.
+Here is a schematic pseudo-code example:
+
+ foo_read_or_write(struct foo_priv *foo, void *data)
+ {
+ lock(&foo->private_lock);
+ add_request_to_io_queue(foo, data);
+ if (foo->num_pending_requests++ == 0)
+ pm_runtime_get(&foo->dev);
+ if (!foo->is_suspended)
+ foo_process_next_request(foo);
+ unlock(&foo->private_lock);
+ }
+
+ foo_io_completion(struct foo_priv *foo, void *req)
+ {
+ lock(&foo->private_lock);
+ if (--foo->num_pending_requests == 0) {
+ pm_runtime_mark_last_busy(&foo->dev);
+ pm_runtime_put_autosuspend(&foo->dev);
+ } else {
+ foo_process_next_request(foo);
+ }
+ unlock(&foo->private_lock);
+ /* Send req result back to the user ... */
+ }
+
+ int foo_runtime_suspend(struct device *dev)
+ {
+ struct foo_priv foo = container_of(dev, ...);
+ int ret = 0;
+
+ lock(&foo->private_lock);
+ if (foo->num_pending_requests > 0) {
+ ret = -EBUSY;
+ } else {
+ /* ... suspend the device ... */
+ foo->is_suspended = 1;
+ }
+ unlock(&foo->private_lock);
+ return ret;
+ }
+
+ int foo_runtime_resume(struct device *dev)
+ {
+ struct foo_priv foo = container_of(dev, ...);
+
+ lock(&foo->private_lock);
+ /* ... resume the device ... */
+ foo->is_suspended = 0;
+ pm_runtime_mark_last_busy(&foo->dev);
+ if (foo->num_pending_requests > 0)
+ foo_process_requests(foo);
+ unlock(&foo->private_lock);
+ return 0;
+ }
+
+The important point is that after foo_io_completion() asks for an autosuspend,
+the foo_runtime_suspend() callback may race with foo_read_or_write().
+Therefore foo_runtime_suspend() has to check whether there are any pending I/O
+requests (while holding the private lock) before allowing the suspend to
+proceed.
+
+In addition, the power.autosuspend_delay field can be changed by user space at
+any time. If a driver cares about this, it can call
+pm_runtime_autosuspend_expiration() from within the ->runtime_suspend()
+callback while holding its private lock. If the function returns a nonzero
+value then the delay has not yet expired and the callback should return
+-EAGAIN.
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 5bd4daa93ef..cd4e100a136 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -9,7 +9,6 @@
#include <linux/sched.h>
#include <linux/pm_runtime.h>
-#include <linux/jiffies.h>
#include "power.h"
static int rpm_resume(struct device *dev, int rpmflags);
@@ -79,6 +78,53 @@ static void pm_runtime_cancel_pending(struct device *dev)
dev->power.request = RPM_REQ_NONE;
}
+/*
+ * pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time.
+ * @dev: Device to handle.
+ *
+ * Compute the autosuspend-delay expiration time based on the device's
+ * power.last_busy time. If the delay has already expired or is disabled
+ * (negative) or the power.use_autosuspend flag isn't set, return 0.
+ * Otherwise return the expiration time in jiffies (adjusted to be nonzero).
+ *
+ * This function may be called either with or without dev->power.lock held.
+ * Either way it can be racy, since power.last_busy may be updated at any time.
+ */
+unsigned long pm_runtime_autosuspend_expiration(struct device *dev)
+{
+ int autosuspend_delay;
+ long elapsed;
+ unsigned long last_busy;
+ unsigned long expires = 0;
+
+ if (!dev->power.use_autosuspend)
+ goto out;
+
+ autosuspend_delay = ACCESS_ONCE(dev->power.autosuspend_delay);
+ if (autosuspend_delay < 0)
+ goto out;
+
+ last_busy = ACCESS_ONCE(dev->power.last_busy);
+ elapsed = jiffies - last_busy;
+ if (elapsed < 0)
+ goto out; /* jiffies has wrapped around. */
+
+ /*
+ * If the autosuspend_delay is >= 1 second, align the timer by rounding
+ * up to the nearest second.
+ */
+ expires = last_busy + msecs_to_jiffies(autosuspend_delay);
+ if (autosuspend_delay >= 1000)
+ expires = round_jiffies(expires);
+ expires += !expires;
+ if (elapsed >= expires - last_busy)
+ expires = 0; /* Already expired. */
+
+ out:
+ return expires;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);
+
/**
* rpm_check_suspend_allowed - Test whether a device may be suspended.
* @dev: Device to test.
@@ -234,6 +280,32 @@ static int rpm_suspend(struct device *dev, int rpmflags)
if (retval)
goto out;
+ /* If the autosuspend_delay time hasn't expired yet, reschedule. */
+ if ((rpmflags & RPM_AUTO)
+ && dev->power.runtime_status != RPM_SUSPENDING) {
+ unsigned long expires = pm_runtime_autosuspend_expiration(dev);
+
+ if (expires != 0) {
+ /* Pending requests need to be canceled. */
+ dev->power.request = RPM_REQ_NONE;
+
+ /*
+ * Optimization: If the timer is already running and is
+ * set to expire at or before the autosuspend delay,
+ * avoid the overhead of resetting it. Just let it
+ * expire; pm_suspend_timer_fn() will take care of the
+ * rest.
+ */
+ if (!(dev->power.timer_expires && time_before_eq(
+ dev->power.timer_expires, expires))) {
+ dev->power.timer_expires = expires;
+ mod_timer(&dev->power.suspend_timer, expires);
+ }
+ dev->power.timer_autosuspends = 1;
+ goto out;
+ }
+ }
+
/* Other scheduled or pending requests need to be canceled. */
pm_runtime_cancel_pending(dev);
@@ -268,7 +340,8 @@ static int rpm_suspend(struct device *dev, int rpmflags)
/* Carry out an asynchronous or a synchronous suspend. */
if (rpmflags & RPM_ASYNC) {
- dev->power.request = RPM_REQ_SUSPEND;
+ dev->power.request = (rpmflags & RPM_AUTO) ?
+ RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
if (!dev->power.request_pending) {
dev->power.request_pending = true;
queue_work(pm_wq, &dev->power.work);
@@ -383,8 +456,15 @@ static int rpm_resume(struct device *dev, int rpmflags)
if (retval)
goto out;
- /* Other scheduled or pending requests need to be canceled. */
- pm_runtime_cancel_pending(dev);
+ /*
+ * Other scheduled or pending requests need to be canceled. Small
+ * optimization: If an autosuspend timer is running, leave it running
+ * rather than cancelling it now only to restart it again in the near
+ * future.
+ */
+ dev->power.request = RPM_REQ_NONE;
+ if (!dev->power.timer_autosuspends)
+ pm_runtime_deactivate_timer(dev);
if (dev->power.runtime_status == RPM_ACTIVE) {
retval = 1;
@@ -568,6 +648,9 @@ static void pm_runtime_work(struct work_struct *work)
case RPM_REQ_SUSPEND:
rpm_suspend(dev, RPM_NOWAIT);
break;
+ case RPM_REQ_AUTOSUSPEND:
+ rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO);
+ break;
case RPM_REQ_RESUME:
rpm_resume(dev, RPM_NOWAIT);
break;
@@ -595,7 +678,8 @@ static void pm_suspend_timer_fn(unsigned long data)
/* If 'expire' is after 'jiffies' we've been called too early. */
if (expires > 0 && !time_after(expires, jiffies)) {
dev->power.timer_expires = 0;
- rpm_suspend(dev, RPM_ASYNC);
+ rpm_suspend(dev, dev->power.timer_autosuspends ?
+ (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC);
}
spin_unlock_irqrestore(&dev->power.lock, flags);
@@ -627,6 +711,7 @@ int pm_schedule_suspend(struct device *dev, unsigned int delay)
dev->power.timer_expires = jiffies + msecs_to_jiffies(delay);
dev->power.timer_expires += !dev->power.timer_expires;
+ dev->power.timer_autosuspends = 0;
mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
out:
@@ -670,7 +755,9 @@ EXPORT_SYMBOL_GPL(__pm_runtime_idle);
* @dev: Device to suspend.
* @rpmflags: Flag bits.
*
- * Carry out a suspend, either synchronous or asynchronous.
+ * If the RPM_GET_PUT flag is set, decrement the device's usage count and
+ * return immediately if it is larger than zero. Then carry out a suspend,
+ * either synchronous or asynchronous.
*
* This routine may be called in atomic context if the RPM_ASYNC flag is set.
*/
@@ -679,6 +766,11 @@ int __pm_runtime_suspend(struct device *dev, int rpmflags)
unsigned long flags;
int retval;
+ if (rpmflags & RPM_GET_PUT) {
+ if (!atomic_dec_and_test(&dev->power.usage_count))
+ return 0;
+ }
+
spin_lock_irqsave(&dev->power.lock, flags);
retval = rpm_suspend(dev, rpmflags);
spin_unlock_irqrestore(&dev->power.lock, flags);
@@ -980,7 +1072,7 @@ void pm_runtime_allow(struct device *dev)
dev->power.runtime_auto = true;
if (atomic_dec_and_test(&dev->power.usage_count))
- rpm_idle(dev, 0);
+ rpm_idle(dev, RPM_AUTO);
out:
spin_unlock_irq(&dev->power.lock);
@@ -1007,6 +1099,86 @@ void pm_runtime_no_callbacks(struct device *dev)
EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);
/**
+ * update_autosuspend - Handle a change to a device's autosuspend settings.
+ * @dev: Device to handle.
+ * @old_delay: The former autosuspend_delay value.
+ * @old_use: The former use_autosuspend value.
+ *
+ * Prevent runtime suspend if the new delay is negative and use_autosuspend is
+ * set; otherwise allow it. Send an idle notification if suspends are allowed.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+static void update_autosuspend(struct device *dev, int old_delay, int old_use)
+{
+ int delay = dev->power.autosuspend_delay;
+
+ /* Should runtime suspend be prevented now? */
+ if (dev->power.use_autosuspend && delay < 0) {
+
+ /* If it used to be allowed then prevent it. */
+ if (!old_use || old_delay >= 0) {
+ atomic_inc(&dev->power.usage_count);
+ rpm_resume(dev, 0);
+ }
+ }
+
+ /* Runtime suspend should be allowed now. */
+ else {
+
+ /* If it used to be prevented then allow it. */
+ if (old_use && old_delay < 0)
+ atomic_dec(&dev->power.usage_count);
+
+ /* Maybe we can autosuspend now. */
+ rpm_idle(dev, RPM_AUTO);
+ }
+}
+
+/**
+ * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
+ * @dev: Device to handle.
+ * @delay: Value of the new delay in milliseconds.
+ *
+ * Set the device's power.autosuspend_delay value. If it changes to negative
+ * and the power.use_autosuspend flag is set, prevent run-time suspends. If it
+ * changes the other way, allow run-time suspends.
+ */
+void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
+{
+ int old_delay, old_use;
+
+ spin_lock_irq(&dev->power.lock);
+ old_delay = dev->power.autosuspend_delay;
+ old_use = dev->power.use_autosuspend;
+ dev->power.autosuspend_delay = delay;
+ update_autosuspend(dev, old_delay, old_use);
+ spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
+
+/**
+ * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
+ * @dev: Device to handle.
+ * @use: New value for use_autosuspend.
+ *
+ * Set the device's power.use_autosuspend flag, and allow or prevent run-time
+ * suspends as needed.
+ */
+void __pm_runtime_use_autosuspend(struct device *dev, bool use)
+{
+ int old_delay, old_use;
+
+ spin_lock_irq(&dev->power.lock);
+ old_delay = dev->power.autosuspend_delay;
+ old_use = dev->power.use_autosuspend;
+ dev->power.use_autosuspend = use;
+ update_autosuspend(dev, old_delay, old_use);
+ spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
+
+/**
* pm_runtime_init - Initialize run-time PM fields in given device object.
* @dev: Device object to initialize.
*/
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index b5708c47ce2..0b1e46bf3e5 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -75,6 +75,18 @@
* attribute is set to "enabled" by bus type code or device drivers and in
* that cases it should be safe to leave the default value.
*
+ * autosuspend_delay_ms - Report/change a device's autosuspend_delay value
+ *
+ * Some drivers don't want to carry out a runtime suspend as soon as a
+ * device becomes idle; they want it always to remain idle for some period
+ * of time before suspending it. This period is the autosuspend_delay
+ * value (expressed in milliseconds) and it can be controlled by the user.
+ * If the value is negative then the device will never be runtime
+ * suspended.
+ *
+ * NOTE: The autosuspend_delay_ms attribute and the autosuspend_delay
+ * value are used only if the driver calls pm_runtime_use_autosuspend().
+ *
* wakeup_count - Report the number of wakeup events related to the device
*/
@@ -173,6 +185,33 @@ static ssize_t rtpm_status_show(struct device *dev,
}
static DEVICE_ATTR(runtime_status, 0444, rtpm_status_show, NULL);
+
+static ssize_t autosuspend_delay_ms_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ if (!dev->power.use_autosuspend)
+ return -EIO;
+ return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
+}
+
+static ssize_t autosuspend_delay_ms_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t n)
+{
+ long delay;
+
+ if (!dev->power.use_autosuspend)
+ return -EIO;
+
+ if (strict_strtol(buf, 10, &delay) != 0 || delay != (int) delay)
+ return -EINVAL;
+
+ pm_runtime_set_autosuspend_delay(dev, delay);
+ return n;
+}
+
+static DEVICE_ATTR(autosuspend_delay_ms, 0644, autosuspend_delay_ms_show,
+ autosuspend_delay_ms_store);
+
#endif
static ssize_t
@@ -428,6 +467,7 @@ static struct attribute *runtime_attrs[] = {
&dev_attr_control.attr,
&dev_attr_runtime_suspended_time.attr,
&dev_attr_runtime_active_time.attr,
+ &dev_attr_autosuspend_delay_ms.attr,
NULL,
};
static struct attribute_group pm_runtime_attr_group = {
diff --git a/include/linux/pm.h b/include/linux/pm.h
index abd81ffaba3..40f3f45702b 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -444,6 +444,9 @@ enum rpm_status {
*
* RPM_REQ_SUSPEND Run the device bus type's ->runtime_suspend() callback
*
+ * RPM_REQ_AUTOSUSPEND Same as RPM_REQ_SUSPEND, but not until the device has
+ * been inactive for as long as power.autosuspend_delay
+ *
* RPM_REQ_RESUME Run the device bus type's ->runtime_resume() callback
*/
@@ -451,6 +454,7 @@ enum rpm_request {
RPM_REQ_NONE = 0,
RPM_REQ_IDLE,
RPM_REQ_SUSPEND,
+ RPM_REQ_AUTOSUSPEND,
RPM_REQ_RESUME,
};
@@ -482,9 +486,13 @@ struct dev_pm_info {
unsigned int run_wake:1;
unsigned int runtime_auto:1;
unsigned int no_callbacks:1;
+ unsigned int use_autosuspend:1;
+ unsigned int timer_autosuspends:1;
enum rpm_request request;
enum rpm_status runtime_status;
int runtime_error;
+ int autosuspend_delay;
+ unsigned long last_busy;
unsigned long active_jiffies;
unsigned long suspended_jiffies;
unsigned long accounting_timestamp;
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index 8ca52f7c357..99ed1aa8f93 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -12,12 +12,15 @@
#include <linux/device.h>
#include <linux/pm.h>
+#include <linux/jiffies.h>
+
/* Runtime PM flag argument bits */
#define RPM_ASYNC 0x01 /* Request is asynchronous */
#define RPM_NOWAIT 0x02 /* Don't wait for concurrent
state change */
#define RPM_GET_PUT 0x04 /* Increment/decrement the
usage_count */
+#define RPM_AUTO 0x08 /* Use autosuspend_delay */
#ifdef CONFIG_PM_RUNTIME
@@ -37,6 +40,9 @@ extern int pm_generic_runtime_idle(struct device *dev);
extern int pm_generic_runtime_suspend(struct device *dev);
extern int pm_generic_runtime_resume(struct device *dev);
extern void pm_runtime_no_callbacks(struct device *dev);
+extern void __pm_runtime_use_autosuspend(struct device *dev, bool use);
+extern void pm_runtime_set_autosuspend_delay(struct device *dev, int delay);
+extern unsigned long pm_runtime_autosuspend_expiration(struct device *dev);
static inline bool pm_children_suspended(struct device *dev)
{
@@ -74,6 +80,11 @@ static inline bool pm_runtime_suspended(struct device *dev)
return dev->power.runtime_status == RPM_SUSPENDED;
}
+static inline void pm_runtime_mark_last_busy(struct device *dev)
+{
+ ACCESS_ONCE(dev->power.last_busy) = jiffies;
+}
+
#else /* !CONFIG_PM_RUNTIME */
static inline int __pm_runtime_idle(struct device *dev, int rpmflags)
@@ -113,6 +124,14 @@ static inline int pm_generic_runtime_suspend(struct device *dev) { return 0; }
static inline int pm_generic_runtime_resume(struct device *dev) { return 0; }
static inline void pm_runtime_no_callbacks(struct device *dev) {}
+static inline void pm_runtime_mark_last_busy(struct device *dev) {}
+static inline void __pm_runtime_use_autosuspend(struct device *dev,
+ bool use) {}
+static inline void pm_runtime_set_autosuspend_delay(struct device *dev,
+ int delay) {}
+static inline unsigned long pm_runtime_autosuspend_expiration(
+ struct device *dev) { return 0; }
+
#endif /* !CONFIG_PM_RUNTIME */
static inline int pm_runtime_idle(struct device *dev)
@@ -125,6 +144,11 @@ static inline int pm_runtime_suspend(struct device *dev)
return __pm_runtime_suspend(dev, 0);
}
+static inline int pm_runtime_autosuspend(struct device *dev)
+{
+ return __pm_runtime_suspend(dev, RPM_AUTO);
+}
+
static inline int pm_runtime_resume(struct device *dev)
{
return __pm_runtime_resume(dev, 0);
@@ -155,11 +179,22 @@ static inline int pm_runtime_put(struct device *dev)
return __pm_runtime_idle(dev, RPM_GET_PUT | RPM_ASYNC);
}
+static inline int pm_runtime_put_autosuspend(struct device *dev)
+{
+ return __pm_runtime_suspend(dev,
+ RPM_GET_PUT | RPM_ASYNC | RPM_AUTO);
+}
+
static inline int pm_runtime_put_sync(struct device *dev)
{
return __pm_runtime_idle(dev, RPM_GET_PUT);
}
+static inline int pm_runtime_put_sync_autosuspend(struct device *dev)
+{
+ return __pm_runtime_suspend(dev, RPM_GET_PUT | RPM_AUTO);
+}
+
static inline int pm_runtime_set_active(struct device *dev)
{
return __pm_runtime_set_status(dev, RPM_ACTIVE);
@@ -175,4 +210,14 @@ static inline void pm_runtime_disable(struct device *dev)
__pm_runtime_disable(dev, true);
}
+static inline void pm_runtime_use_autosuspend(struct device *dev)
+{
+ __pm_runtime_use_autosuspend(dev, true);
+}
+
+static inline void pm_runtime_dont_use_autosuspend(struct device *dev)
+{
+ __pm_runtime_use_autosuspend(dev, false);
+}
+
#endif