kernel_optimize_test/drivers/acpi/device_pm.c
Rafael J. Wysocki bc9b6407bd ACPI / PM: Rework the handling of devices depending on power resources
Commit 0090def6 (ACPI: Add interface to register/unregister device
to/from power resources) made it possible to indicate to the ACPI
core that if the given device depends on any power resources, then
it should be resumed as soon as all of the power resources required
by it to transition to the D0 power state have been turned on.

Unfortunately, however, this was a mistake, because all devices
depending on power resources should be treated this way (i.e. they
should be resumed when all power resources required by their D0
state have been turned on) and for the majority of those devices
the ACPI core can figure out by itself which (physical) devices
depend on what power resources.

For this reason, replace the code added by commit 0090def6 with a
new, much more straightforward, mechanism that will be used
internally by the ACPI core and remove all references to that code
from kernel subsystems using ACPI.

For the cases when there are (physical) devices that should be
resumed whenever a not directly related ACPI device node goes into
D0 as a result of power resources configuration changes, like in
the SATA case, add two new routines, acpi_dev_pm_add_dependent()
and acpi_dev_pm_remove_dependent(), allowing subsystems to manage
such dependencies.  Convert the SATA subsystem to use the new
functions accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-01-17 14:11:05 +01:00

724 lines
22 KiB
C

/*
* drivers/acpi/device_pm.c - ACPI device power management routines.
*
* Copyright (C) 2012, Intel Corp.
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/device.h>
#include <linux/export.h>
#include <linux/mutex.h>
#include <linux/pm_qos.h>
#include <linux/pm_runtime.h>
#include <acpi/acpi.h>
#include <acpi/acpi_bus.h>
static DEFINE_MUTEX(acpi_pm_notifier_lock);
/**
* acpi_add_pm_notifier - Register PM notifier for given ACPI device.
* @adev: ACPI device to add the notifier for.
* @context: Context information to pass to the notifier routine.
*
* NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
* PM wakeup events. For example, wakeup events may be generated for bridges
* if one of the devices below the bridge is signaling wakeup, even if the
* bridge itself doesn't have a wakeup GPE associated with it.
*/
acpi_status acpi_add_pm_notifier(struct acpi_device *adev,
acpi_notify_handler handler, void *context)
{
acpi_status status = AE_ALREADY_EXISTS;
mutex_lock(&acpi_pm_notifier_lock);
if (adev->wakeup.flags.notifier_present)
goto out;
status = acpi_install_notify_handler(adev->handle,
ACPI_SYSTEM_NOTIFY,
handler, context);
if (ACPI_FAILURE(status))
goto out;
adev->wakeup.flags.notifier_present = true;
out:
mutex_unlock(&acpi_pm_notifier_lock);
return status;
}
/**
* acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
* @adev: ACPI device to remove the notifier from.
*/
acpi_status acpi_remove_pm_notifier(struct acpi_device *adev,
acpi_notify_handler handler)
{
acpi_status status = AE_BAD_PARAMETER;
mutex_lock(&acpi_pm_notifier_lock);
if (!adev->wakeup.flags.notifier_present)
goto out;
status = acpi_remove_notify_handler(adev->handle,
ACPI_SYSTEM_NOTIFY,
handler);
if (ACPI_FAILURE(status))
goto out;
adev->wakeup.flags.notifier_present = false;
out:
mutex_unlock(&acpi_pm_notifier_lock);
return status;
}
/**
* acpi_device_power_state - Get preferred power state of ACPI device.
* @dev: Device whose preferred target power state to return.
* @adev: ACPI device node corresponding to @dev.
* @target_state: System state to match the resultant device state.
* @d_max_in: Deepest low-power state to take into consideration.
* @d_min_p: Location to store the upper limit of the allowed states range.
* Return value: Preferred power state of the device on success, -ENODEV
* (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
*
* Find the lowest power (highest number) ACPI device power state that the
* device can be in while the system is in the state represented by
* @target_state. If @d_min_p is set, the highest power (lowest number) device
* power state that @dev can be in for the given system sleep state is stored
* at the location pointed to by it.
*
* Callers must ensure that @dev and @adev are valid pointers and that @adev
* actually corresponds to @dev before using this function.
*/
int acpi_device_power_state(struct device *dev, struct acpi_device *adev,
u32 target_state, int d_max_in, int *d_min_p)
{
char acpi_method[] = "_SxD";
unsigned long long d_min, d_max;
bool wakeup = false;
if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
return -EINVAL;
if (d_max_in > ACPI_STATE_D3_HOT) {
enum pm_qos_flags_status stat;
stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
if (stat == PM_QOS_FLAGS_ALL)
d_max_in = ACPI_STATE_D3_HOT;
}
acpi_method[2] = '0' + target_state;
/*
* If the sleep state is S0, the lowest limit from ACPI is D3,
* but if the device has _S0W, we will use the value from _S0W
* as the lowest limit from ACPI. Finally, we will constrain
* the lowest limit with the specified one.
*/
d_min = ACPI_STATE_D0;
d_max = ACPI_STATE_D3;
/*
* If present, _SxD methods return the minimum D-state (highest power
* state) we can use for the corresponding S-states. Otherwise, the
* minimum D-state is D0 (ACPI 3.x).
*
* NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
* provided -- that's our fault recovery, we ignore retval.
*/
if (target_state > ACPI_STATE_S0) {
acpi_evaluate_integer(adev->handle, acpi_method, NULL, &d_min);
wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
&& adev->wakeup.sleep_state >= target_state;
} else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
PM_QOS_FLAGS_NONE) {
wakeup = adev->wakeup.flags.valid;
}
/*
* If _PRW says we can wake up the system from the target sleep state,
* the D-state returned by _SxD is sufficient for that (we assume a
* wakeup-aware driver if wake is set). Still, if _SxW exists
* (ACPI 3.x), it should return the maximum (lowest power) D-state that
* can wake the system. _S0W may be valid, too.
*/
if (wakeup) {
acpi_status status;
acpi_method[3] = 'W';
status = acpi_evaluate_integer(adev->handle, acpi_method, NULL,
&d_max);
if (ACPI_FAILURE(status)) {
if (target_state != ACPI_STATE_S0 ||
status != AE_NOT_FOUND)
d_max = d_min;
} else if (d_max < d_min) {
/* Warn the user of the broken DSDT */
printk(KERN_WARNING "ACPI: Wrong value from %s\n",
acpi_method);
/* Sanitize it */
d_min = d_max;
}
}
if (d_max_in < d_min)
return -EINVAL;
if (d_min_p)
*d_min_p = d_min;
/* constrain d_max with specified lowest limit (max number) */
if (d_max > d_max_in) {
for (d_max = d_max_in; d_max > d_min; d_max--) {
if (adev->power.states[d_max].flags.valid)
break;
}
}
return d_max;
}
EXPORT_SYMBOL_GPL(acpi_device_power_state);
/**
* acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
* @dev: Device whose preferred target power state to return.
* @d_min_p: Location to store the upper limit of the allowed states range.
* @d_max_in: Deepest low-power state to take into consideration.
* Return value: Preferred power state of the device on success, -ENODEV
* (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
*
* The caller must ensure that @dev is valid before using this function.
*/
int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
struct acpi_device *adev;
if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
return -ENODEV;
}
return acpi_device_power_state(dev, adev, acpi_target_system_state(),
d_max_in, d_min_p);
}
EXPORT_SYMBOL(acpi_pm_device_sleep_state);
#ifdef CONFIG_PM_RUNTIME
/**
* acpi_wakeup_device - Wakeup notification handler for ACPI devices.
* @handle: ACPI handle of the device the notification is for.
* @event: Type of the signaled event.
* @context: Device corresponding to @handle.
*/
static void acpi_wakeup_device(acpi_handle handle, u32 event, void *context)
{
struct device *dev = context;
if (event == ACPI_NOTIFY_DEVICE_WAKE && dev) {
pm_wakeup_event(dev, 0);
pm_runtime_resume(dev);
}
}
/**
* __acpi_device_run_wake - Enable/disable runtime remote wakeup for device.
* @adev: ACPI device to enable/disable the remote wakeup for.
* @enable: Whether to enable or disable the wakeup functionality.
*
* Enable/disable the GPE associated with @adev so that it can generate
* wakeup signals for the device in response to external (remote) events and
* enable/disable device wakeup power.
*
* Callers must ensure that @adev is a valid ACPI device node before executing
* this function.
*/
int __acpi_device_run_wake(struct acpi_device *adev, bool enable)
{
struct acpi_device_wakeup *wakeup = &adev->wakeup;
if (enable) {
acpi_status res;
int error;
error = acpi_enable_wakeup_device_power(adev, ACPI_STATE_S0);
if (error)
return error;
res = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
if (ACPI_FAILURE(res)) {
acpi_disable_wakeup_device_power(adev);
return -EIO;
}
} else {
acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
acpi_disable_wakeup_device_power(adev);
}
return 0;
}
/**
* acpi_pm_device_run_wake - Enable/disable remote wakeup for given device.
* @dev: Device to enable/disable the platform to wake up.
* @enable: Whether to enable or disable the wakeup functionality.
*/
int acpi_pm_device_run_wake(struct device *phys_dev, bool enable)
{
struct acpi_device *adev;
acpi_handle handle;
if (!device_run_wake(phys_dev))
return -EINVAL;
handle = DEVICE_ACPI_HANDLE(phys_dev);
if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
dev_dbg(phys_dev, "ACPI handle without context in %s!\n",
__func__);
return -ENODEV;
}
return __acpi_device_run_wake(adev, enable);
}
EXPORT_SYMBOL(acpi_pm_device_run_wake);
#else
static inline void acpi_wakeup_device(acpi_handle handle, u32 event,
void *context) {}
#endif /* CONFIG_PM_RUNTIME */
#ifdef CONFIG_PM_SLEEP
/**
* __acpi_device_sleep_wake - Enable or disable device to wake up the system.
* @dev: Device to enable/desible to wake up the system.
* @target_state: System state the device is supposed to wake up from.
* @enable: Whether to enable or disable @dev to wake up the system.
*/
int __acpi_device_sleep_wake(struct acpi_device *adev, u32 target_state,
bool enable)
{
return enable ?
acpi_enable_wakeup_device_power(adev, target_state) :
acpi_disable_wakeup_device_power(adev);
}
/**
* acpi_pm_device_sleep_wake - Enable or disable device to wake up the system.
* @dev: Device to enable/desible to wake up the system from sleep states.
* @enable: Whether to enable or disable @dev to wake up the system.
*/
int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
{
acpi_handle handle;
struct acpi_device *adev;
int error;
if (!device_can_wakeup(dev))
return -EINVAL;
handle = DEVICE_ACPI_HANDLE(dev);
if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
return -ENODEV;
}
error = __acpi_device_sleep_wake(adev, acpi_target_system_state(),
enable);
if (!error)
dev_info(dev, "System wakeup %s by ACPI\n",
enable ? "enabled" : "disabled");
return error;
}
#endif /* CONFIG_PM_SLEEP */
/**
* acpi_dev_pm_get_node - Get ACPI device node for the given physical device.
* @dev: Device to get the ACPI node for.
*/
struct acpi_device *acpi_dev_pm_get_node(struct device *dev)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
struct acpi_device *adev;
return handle && !acpi_bus_get_device(handle, &adev) ? adev : NULL;
}
/**
* acpi_dev_pm_low_power - Put ACPI device into a low-power state.
* @dev: Device to put into a low-power state.
* @adev: ACPI device node corresponding to @dev.
* @system_state: System state to choose the device state for.
*/
static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
u32 system_state)
{
int power_state;
if (!acpi_device_power_manageable(adev))
return 0;
power_state = acpi_device_power_state(dev, adev, system_state,
ACPI_STATE_D3, NULL);
if (power_state < ACPI_STATE_D0 || power_state > ACPI_STATE_D3)
return -EIO;
return acpi_device_set_power(adev, power_state);
}
/**
* acpi_dev_pm_full_power - Put ACPI device into the full-power state.
* @adev: ACPI device node to put into the full-power state.
*/
static int acpi_dev_pm_full_power(struct acpi_device *adev)
{
return acpi_device_power_manageable(adev) ?
acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
}
#ifdef CONFIG_PM_RUNTIME
/**
* acpi_dev_runtime_suspend - Put device into a low-power state using ACPI.
* @dev: Device to put into a low-power state.
*
* Put the given device into a runtime low-power state using the standard ACPI
* mechanism. Set up remote wakeup if desired, choose the state to put the
* device into (this checks if remote wakeup is expected to work too), and set
* the power state of the device.
*/
int acpi_dev_runtime_suspend(struct device *dev)
{
struct acpi_device *adev = acpi_dev_pm_get_node(dev);
bool remote_wakeup;
int error;
if (!adev)
return 0;
remote_wakeup = dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) >
PM_QOS_FLAGS_NONE;
error = __acpi_device_run_wake(adev, remote_wakeup);
if (remote_wakeup && error)
return -EAGAIN;
error = acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
if (error)
__acpi_device_run_wake(adev, false);
return error;
}
EXPORT_SYMBOL_GPL(acpi_dev_runtime_suspend);
/**
* acpi_dev_runtime_resume - Put device into the full-power state using ACPI.
* @dev: Device to put into the full-power state.
*
* Put the given device into the full-power state using the standard ACPI
* mechanism at run time. Set the power state of the device to ACPI D0 and
* disable remote wakeup.
*/
int acpi_dev_runtime_resume(struct device *dev)
{
struct acpi_device *adev = acpi_dev_pm_get_node(dev);
int error;
if (!adev)
return 0;
error = acpi_dev_pm_full_power(adev);
__acpi_device_run_wake(adev, false);
return error;
}
EXPORT_SYMBOL_GPL(acpi_dev_runtime_resume);
/**
* acpi_subsys_runtime_suspend - Suspend device using ACPI.
* @dev: Device to suspend.
*
* Carry out the generic runtime suspend procedure for @dev and use ACPI to put
* it into a runtime low-power state.
*/
int acpi_subsys_runtime_suspend(struct device *dev)
{
int ret = pm_generic_runtime_suspend(dev);
return ret ? ret : acpi_dev_runtime_suspend(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
/**
* acpi_subsys_runtime_resume - Resume device using ACPI.
* @dev: Device to Resume.
*
* Use ACPI to put the given device into the full-power state and carry out the
* generic runtime resume procedure for it.
*/
int acpi_subsys_runtime_resume(struct device *dev)
{
int ret = acpi_dev_runtime_resume(dev);
return ret ? ret : pm_generic_runtime_resume(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
#endif /* CONFIG_PM_RUNTIME */
#ifdef CONFIG_PM_SLEEP
/**
* acpi_dev_suspend_late - Put device into a low-power state using ACPI.
* @dev: Device to put into a low-power state.
*
* Put the given device into a low-power state during system transition to a
* sleep state using the standard ACPI mechanism. Set up system wakeup if
* desired, choose the state to put the device into (this checks if system
* wakeup is expected to work too), and set the power state of the device.
*/
int acpi_dev_suspend_late(struct device *dev)
{
struct acpi_device *adev = acpi_dev_pm_get_node(dev);
u32 target_state;
bool wakeup;
int error;
if (!adev)
return 0;
target_state = acpi_target_system_state();
wakeup = device_may_wakeup(dev);
error = __acpi_device_sleep_wake(adev, target_state, wakeup);
if (wakeup && error)
return error;
error = acpi_dev_pm_low_power(dev, adev, target_state);
if (error)
__acpi_device_sleep_wake(adev, ACPI_STATE_UNKNOWN, false);
return error;
}
EXPORT_SYMBOL_GPL(acpi_dev_suspend_late);
/**
* acpi_dev_resume_early - Put device into the full-power state using ACPI.
* @dev: Device to put into the full-power state.
*
* Put the given device into the full-power state using the standard ACPI
* mechanism during system transition to the working state. Set the power
* state of the device to ACPI D0 and disable remote wakeup.
*/
int acpi_dev_resume_early(struct device *dev)
{
struct acpi_device *adev = acpi_dev_pm_get_node(dev);
int error;
if (!adev)
return 0;
error = acpi_dev_pm_full_power(adev);
__acpi_device_sleep_wake(adev, ACPI_STATE_UNKNOWN, false);
return error;
}
EXPORT_SYMBOL_GPL(acpi_dev_resume_early);
/**
* acpi_subsys_prepare - Prepare device for system transition to a sleep state.
* @dev: Device to prepare.
*/
int acpi_subsys_prepare(struct device *dev)
{
/*
* Follow PCI and resume devices suspended at run time before running
* their system suspend callbacks.
*/
pm_runtime_resume(dev);
return pm_generic_prepare(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
/**
* acpi_subsys_suspend_late - Suspend device using ACPI.
* @dev: Device to suspend.
*
* Carry out the generic late suspend procedure for @dev and use ACPI to put
* it into a low-power state during system transition into a sleep state.
*/
int acpi_subsys_suspend_late(struct device *dev)
{
int ret = pm_generic_suspend_late(dev);
return ret ? ret : acpi_dev_suspend_late(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
/**
* acpi_subsys_resume_early - Resume device using ACPI.
* @dev: Device to Resume.
*
* Use ACPI to put the given device into the full-power state and carry out the
* generic early resume procedure for it during system transition into the
* working state.
*/
int acpi_subsys_resume_early(struct device *dev)
{
int ret = acpi_dev_resume_early(dev);
return ret ? ret : pm_generic_resume_early(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_resume_early);
#endif /* CONFIG_PM_SLEEP */
static struct dev_pm_domain acpi_general_pm_domain = {
.ops = {
#ifdef CONFIG_PM_RUNTIME
.runtime_suspend = acpi_subsys_runtime_suspend,
.runtime_resume = acpi_subsys_runtime_resume,
.runtime_idle = pm_generic_runtime_idle,
#endif
#ifdef CONFIG_PM_SLEEP
.prepare = acpi_subsys_prepare,
.suspend_late = acpi_subsys_suspend_late,
.resume_early = acpi_subsys_resume_early,
.poweroff_late = acpi_subsys_suspend_late,
.restore_early = acpi_subsys_resume_early,
#endif
},
};
/**
* acpi_dev_pm_attach - Prepare device for ACPI power management.
* @dev: Device to prepare.
* @power_on: Whether or not to power on the device.
*
* If @dev has a valid ACPI handle that has a valid struct acpi_device object
* attached to it, install a wakeup notification handler for the device and
* add it to the general ACPI PM domain. If @power_on is set, the device will
* be put into the ACPI D0 state before the function returns.
*
* This assumes that the @dev's bus type uses generic power management callbacks
* (or doesn't use any power management callbacks at all).
*
* Callers must ensure proper synchronization of this function with power
* management callbacks.
*/
int acpi_dev_pm_attach(struct device *dev, bool power_on)
{
struct acpi_device *adev = acpi_dev_pm_get_node(dev);
if (!adev)
return -ENODEV;
if (dev->pm_domain)
return -EEXIST;
acpi_add_pm_notifier(adev, acpi_wakeup_device, dev);
dev->pm_domain = &acpi_general_pm_domain;
if (power_on) {
acpi_dev_pm_full_power(adev);
__acpi_device_run_wake(adev, false);
}
return 0;
}
EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
/**
* acpi_dev_pm_detach - Remove ACPI power management from the device.
* @dev: Device to take care of.
* @power_off: Whether or not to try to remove power from the device.
*
* Remove the device from the general ACPI PM domain and remove its wakeup
* notifier. If @power_off is set, additionally remove power from the device if
* possible.
*
* Callers must ensure proper synchronization of this function with power
* management callbacks.
*/
void acpi_dev_pm_detach(struct device *dev, bool power_off)
{
struct acpi_device *adev = acpi_dev_pm_get_node(dev);
if (adev && dev->pm_domain == &acpi_general_pm_domain) {
dev->pm_domain = NULL;
acpi_remove_pm_notifier(adev, acpi_wakeup_device);
if (power_off) {
/*
* If the device's PM QoS resume latency limit or flags
* have been exposed to user space, they have to be
* hidden at this point, so that they don't affect the
* choice of the low-power state to put the device into.
*/
dev_pm_qos_hide_latency_limit(dev);
dev_pm_qos_hide_flags(dev);
__acpi_device_run_wake(adev, false);
acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
}
}
}
EXPORT_SYMBOL_GPL(acpi_dev_pm_detach);
/**
* acpi_dev_pm_add_dependent - Add physical device depending for PM.
* @handle: Handle of ACPI device node.
* @depdev: Device depending on that node for PM.
*/
void acpi_dev_pm_add_dependent(acpi_handle handle, struct device *depdev)
{
struct acpi_device_physical_node *dep;
struct acpi_device *adev;
if (!depdev || acpi_bus_get_device(handle, &adev))
return;
mutex_lock(&adev->physical_node_lock);
list_for_each_entry(dep, &adev->power_dependent, node)
if (dep->dev == depdev)
goto out;
dep = kzalloc(sizeof(*dep), GFP_KERNEL);
if (dep) {
dep->dev = depdev;
list_add_tail(&dep->node, &adev->power_dependent);
}
out:
mutex_unlock(&adev->physical_node_lock);
}
EXPORT_SYMBOL_GPL(acpi_dev_pm_add_dependent);
/**
* acpi_dev_pm_remove_dependent - Remove physical device depending for PM.
* @handle: Handle of ACPI device node.
* @depdev: Device depending on that node for PM.
*/
void acpi_dev_pm_remove_dependent(acpi_handle handle, struct device *depdev)
{
struct acpi_device_physical_node *dep;
struct acpi_device *adev;
if (!depdev || acpi_bus_get_device(handle, &adev))
return;
mutex_lock(&adev->physical_node_lock);
list_for_each_entry(dep, &adev->power_dependent, node)
if (dep->dev == depdev) {
list_del(&dep->node);
kfree(dep);
break;
}
mutex_unlock(&adev->physical_node_lock);
}
EXPORT_SYMBOL_GPL(acpi_dev_pm_remove_dependent);