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Diffstat (limited to 'drivers/base/power/runtime.c')
-rw-r--r--drivers/base/power/runtime.c186
1 files changed, 179 insertions, 7 deletions
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.
*/