kernel-ark/drivers/base/power/main.c
Romit Dasgupta e528e87689 PM: Fix warning on suspend errors
Fixes the point where we need to complete the power transition when
device suspend fails, so that we don't print warnings about devices
added to the device hierarchy after a failing suspend.

[rjw: Modified changelog.]

Signed-off-by: Romit Dasgupta <romit@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-11-03 11:03:33 +01:00

830 lines
20 KiB
C

/*
* drivers/base/power/main.c - Where the driver meets power management.
*
* Copyright (c) 2003 Patrick Mochel
* Copyright (c) 2003 Open Source Development Lab
*
* This file is released under the GPLv2
*
*
* The driver model core calls device_pm_add() when a device is registered.
* This will intialize the embedded device_pm_info object in the device
* and add it to the list of power-controlled devices. sysfs entries for
* controlling device power management will also be added.
*
* A separate list is used for keeping track of power info, because the power
* domain dependencies may differ from the ancestral dependencies that the
* subsystem list maintains.
*/
#include <linux/device.h>
#include <linux/kallsyms.h>
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/resume-trace.h>
#include <linux/rwsem.h>
#include <linux/interrupt.h>
#include "../base.h"
#include "power.h"
/*
* The entries in the dpm_list list are in a depth first order, simply
* because children are guaranteed to be discovered after parents, and
* are inserted at the back of the list on discovery.
*
* Since device_pm_add() may be called with a device semaphore held,
* we must never try to acquire a device semaphore while holding
* dpm_list_mutex.
*/
LIST_HEAD(dpm_list);
static DEFINE_MUTEX(dpm_list_mtx);
/*
* Set once the preparation of devices for a PM transition has started, reset
* before starting to resume devices. Protected by dpm_list_mtx.
*/
static bool transition_started;
/**
* device_pm_init - Initialize the PM-related part of a device object.
* @dev: Device object being initialized.
*/
void device_pm_init(struct device *dev)
{
dev->power.status = DPM_ON;
pm_runtime_init(dev);
}
/**
* device_pm_lock - Lock the list of active devices used by the PM core.
*/
void device_pm_lock(void)
{
mutex_lock(&dpm_list_mtx);
}
/**
* device_pm_unlock - Unlock the list of active devices used by the PM core.
*/
void device_pm_unlock(void)
{
mutex_unlock(&dpm_list_mtx);
}
/**
* device_pm_add - Add a device to the PM core's list of active devices.
* @dev: Device to add to the list.
*/
void device_pm_add(struct device *dev)
{
pr_debug("PM: Adding info for %s:%s\n",
dev->bus ? dev->bus->name : "No Bus",
kobject_name(&dev->kobj));
mutex_lock(&dpm_list_mtx);
if (dev->parent) {
if (dev->parent->power.status >= DPM_SUSPENDING)
dev_warn(dev, "parent %s should not be sleeping\n",
dev_name(dev->parent));
} else if (transition_started) {
/*
* We refuse to register parentless devices while a PM
* transition is in progress in order to avoid leaving them
* unhandled down the road
*/
dev_WARN(dev, "Parentless device registered during a PM transaction\n");
}
list_add_tail(&dev->power.entry, &dpm_list);
mutex_unlock(&dpm_list_mtx);
}
/**
* device_pm_remove - Remove a device from the PM core's list of active devices.
* @dev: Device to be removed from the list.
*/
void device_pm_remove(struct device *dev)
{
pr_debug("PM: Removing info for %s:%s\n",
dev->bus ? dev->bus->name : "No Bus",
kobject_name(&dev->kobj));
mutex_lock(&dpm_list_mtx);
list_del_init(&dev->power.entry);
mutex_unlock(&dpm_list_mtx);
pm_runtime_remove(dev);
}
/**
* device_pm_move_before - Move device in the PM core's list of active devices.
* @deva: Device to move in dpm_list.
* @devb: Device @deva should come before.
*/
void device_pm_move_before(struct device *deva, struct device *devb)
{
pr_debug("PM: Moving %s:%s before %s:%s\n",
deva->bus ? deva->bus->name : "No Bus",
kobject_name(&deva->kobj),
devb->bus ? devb->bus->name : "No Bus",
kobject_name(&devb->kobj));
/* Delete deva from dpm_list and reinsert before devb. */
list_move_tail(&deva->power.entry, &devb->power.entry);
}
/**
* device_pm_move_after - Move device in the PM core's list of active devices.
* @deva: Device to move in dpm_list.
* @devb: Device @deva should come after.
*/
void device_pm_move_after(struct device *deva, struct device *devb)
{
pr_debug("PM: Moving %s:%s after %s:%s\n",
deva->bus ? deva->bus->name : "No Bus",
kobject_name(&deva->kobj),
devb->bus ? devb->bus->name : "No Bus",
kobject_name(&devb->kobj));
/* Delete deva from dpm_list and reinsert after devb. */
list_move(&deva->power.entry, &devb->power.entry);
}
/**
* device_pm_move_last - Move device to end of the PM core's list of devices.
* @dev: Device to move in dpm_list.
*/
void device_pm_move_last(struct device *dev)
{
pr_debug("PM: Moving %s:%s to end of list\n",
dev->bus ? dev->bus->name : "No Bus",
kobject_name(&dev->kobj));
list_move_tail(&dev->power.entry, &dpm_list);
}
/**
* pm_op - Execute the PM operation appropriate for given PM event.
* @dev: Device to handle.
* @ops: PM operations to choose from.
* @state: PM transition of the system being carried out.
*/
static int pm_op(struct device *dev,
const struct dev_pm_ops *ops,
pm_message_t state)
{
int error = 0;
switch (state.event) {
#ifdef CONFIG_SUSPEND
case PM_EVENT_SUSPEND:
if (ops->suspend) {
error = ops->suspend(dev);
suspend_report_result(ops->suspend, error);
}
break;
case PM_EVENT_RESUME:
if (ops->resume) {
error = ops->resume(dev);
suspend_report_result(ops->resume, error);
}
break;
#endif /* CONFIG_SUSPEND */
#ifdef CONFIG_HIBERNATION
case PM_EVENT_FREEZE:
case PM_EVENT_QUIESCE:
if (ops->freeze) {
error = ops->freeze(dev);
suspend_report_result(ops->freeze, error);
}
break;
case PM_EVENT_HIBERNATE:
if (ops->poweroff) {
error = ops->poweroff(dev);
suspend_report_result(ops->poweroff, error);
}
break;
case PM_EVENT_THAW:
case PM_EVENT_RECOVER:
if (ops->thaw) {
error = ops->thaw(dev);
suspend_report_result(ops->thaw, error);
}
break;
case PM_EVENT_RESTORE:
if (ops->restore) {
error = ops->restore(dev);
suspend_report_result(ops->restore, error);
}
break;
#endif /* CONFIG_HIBERNATION */
default:
error = -EINVAL;
}
return error;
}
/**
* pm_noirq_op - Execute the PM operation appropriate for given PM event.
* @dev: Device to handle.
* @ops: PM operations to choose from.
* @state: PM transition of the system being carried out.
*
* The driver of @dev will not receive interrupts while this function is being
* executed.
*/
static int pm_noirq_op(struct device *dev,
const struct dev_pm_ops *ops,
pm_message_t state)
{
int error = 0;
switch (state.event) {
#ifdef CONFIG_SUSPEND
case PM_EVENT_SUSPEND:
if (ops->suspend_noirq) {
error = ops->suspend_noirq(dev);
suspend_report_result(ops->suspend_noirq, error);
}
break;
case PM_EVENT_RESUME:
if (ops->resume_noirq) {
error = ops->resume_noirq(dev);
suspend_report_result(ops->resume_noirq, error);
}
break;
#endif /* CONFIG_SUSPEND */
#ifdef CONFIG_HIBERNATION
case PM_EVENT_FREEZE:
case PM_EVENT_QUIESCE:
if (ops->freeze_noirq) {
error = ops->freeze_noirq(dev);
suspend_report_result(ops->freeze_noirq, error);
}
break;
case PM_EVENT_HIBERNATE:
if (ops->poweroff_noirq) {
error = ops->poweroff_noirq(dev);
suspend_report_result(ops->poweroff_noirq, error);
}
break;
case PM_EVENT_THAW:
case PM_EVENT_RECOVER:
if (ops->thaw_noirq) {
error = ops->thaw_noirq(dev);
suspend_report_result(ops->thaw_noirq, error);
}
break;
case PM_EVENT_RESTORE:
if (ops->restore_noirq) {
error = ops->restore_noirq(dev);
suspend_report_result(ops->restore_noirq, error);
}
break;
#endif /* CONFIG_HIBERNATION */
default:
error = -EINVAL;
}
return error;
}
static char *pm_verb(int event)
{
switch (event) {
case PM_EVENT_SUSPEND:
return "suspend";
case PM_EVENT_RESUME:
return "resume";
case PM_EVENT_FREEZE:
return "freeze";
case PM_EVENT_QUIESCE:
return "quiesce";
case PM_EVENT_HIBERNATE:
return "hibernate";
case PM_EVENT_THAW:
return "thaw";
case PM_EVENT_RESTORE:
return "restore";
case PM_EVENT_RECOVER:
return "recover";
default:
return "(unknown PM event)";
}
}
static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
{
dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
", may wakeup" : "");
}
static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
int error)
{
printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
kobject_name(&dev->kobj), pm_verb(state.event), info, error);
}
/*------------------------- Resume routines -------------------------*/
/**
* device_resume_noirq - Execute an "early resume" callback for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
*
* The driver of @dev will not receive interrupts while this function is being
* executed.
*/
static int device_resume_noirq(struct device *dev, pm_message_t state)
{
int error = 0;
TRACE_DEVICE(dev);
TRACE_RESUME(0);
if (!dev->bus)
goto End;
if (dev->bus->pm) {
pm_dev_dbg(dev, state, "EARLY ");
error = pm_noirq_op(dev, dev->bus->pm, state);
}
End:
TRACE_RESUME(error);
return error;
}
/**
* dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
* @state: PM transition of the system being carried out.
*
* Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
* enable device drivers to receive interrupts.
*/
void dpm_resume_noirq(pm_message_t state)
{
struct device *dev;
mutex_lock(&dpm_list_mtx);
transition_started = false;
list_for_each_entry(dev, &dpm_list, power.entry)
if (dev->power.status > DPM_OFF) {
int error;
dev->power.status = DPM_OFF;
error = device_resume_noirq(dev, state);
if (error)
pm_dev_err(dev, state, " early", error);
}
mutex_unlock(&dpm_list_mtx);
resume_device_irqs();
}
EXPORT_SYMBOL_GPL(dpm_resume_noirq);
/**
* device_resume - Execute "resume" callbacks for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
*/
static int device_resume(struct device *dev, pm_message_t state)
{
int error = 0;
TRACE_DEVICE(dev);
TRACE_RESUME(0);
down(&dev->sem);
if (dev->bus) {
if (dev->bus->pm) {
pm_dev_dbg(dev, state, "");
error = pm_op(dev, dev->bus->pm, state);
} else if (dev->bus->resume) {
pm_dev_dbg(dev, state, "legacy ");
error = dev->bus->resume(dev);
}
if (error)
goto End;
}
if (dev->type) {
if (dev->type->pm) {
pm_dev_dbg(dev, state, "type ");
error = pm_op(dev, dev->type->pm, state);
}
if (error)
goto End;
}
if (dev->class) {
if (dev->class->pm) {
pm_dev_dbg(dev, state, "class ");
error = pm_op(dev, dev->class->pm, state);
} else if (dev->class->resume) {
pm_dev_dbg(dev, state, "legacy class ");
error = dev->class->resume(dev);
}
}
End:
up(&dev->sem);
TRACE_RESUME(error);
return error;
}
/**
* dpm_resume - Execute "resume" callbacks for non-sysdev devices.
* @state: PM transition of the system being carried out.
*
* Execute the appropriate "resume" callback for all devices whose status
* indicates that they are suspended.
*/
static void dpm_resume(pm_message_t state)
{
struct list_head list;
INIT_LIST_HEAD(&list);
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_list)) {
struct device *dev = to_device(dpm_list.next);
get_device(dev);
if (dev->power.status >= DPM_OFF) {
int error;
dev->power.status = DPM_RESUMING;
mutex_unlock(&dpm_list_mtx);
error = device_resume(dev, state);
mutex_lock(&dpm_list_mtx);
if (error)
pm_dev_err(dev, state, "", error);
} else if (dev->power.status == DPM_SUSPENDING) {
/* Allow new children of the device to be registered */
dev->power.status = DPM_RESUMING;
}
if (!list_empty(&dev->power.entry))
list_move_tail(&dev->power.entry, &list);
put_device(dev);
}
list_splice(&list, &dpm_list);
mutex_unlock(&dpm_list_mtx);
}
/**
* device_complete - Complete a PM transition for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
*/
static void device_complete(struct device *dev, pm_message_t state)
{
down(&dev->sem);
if (dev->class && dev->class->pm && dev->class->pm->complete) {
pm_dev_dbg(dev, state, "completing class ");
dev->class->pm->complete(dev);
}
if (dev->type && dev->type->pm && dev->type->pm->complete) {
pm_dev_dbg(dev, state, "completing type ");
dev->type->pm->complete(dev);
}
if (dev->bus && dev->bus->pm && dev->bus->pm->complete) {
pm_dev_dbg(dev, state, "completing ");
dev->bus->pm->complete(dev);
}
up(&dev->sem);
}
/**
* dpm_complete - Complete a PM transition for all non-sysdev devices.
* @state: PM transition of the system being carried out.
*
* Execute the ->complete() callbacks for all devices whose PM status is not
* DPM_ON (this allows new devices to be registered).
*/
static void dpm_complete(pm_message_t state)
{
struct list_head list;
INIT_LIST_HEAD(&list);
mutex_lock(&dpm_list_mtx);
transition_started = false;
while (!list_empty(&dpm_list)) {
struct device *dev = to_device(dpm_list.prev);
get_device(dev);
if (dev->power.status > DPM_ON) {
dev->power.status = DPM_ON;
mutex_unlock(&dpm_list_mtx);
device_complete(dev, state);
pm_runtime_put_noidle(dev);
mutex_lock(&dpm_list_mtx);
}
if (!list_empty(&dev->power.entry))
list_move(&dev->power.entry, &list);
put_device(dev);
}
list_splice(&list, &dpm_list);
mutex_unlock(&dpm_list_mtx);
}
/**
* dpm_resume_end - Execute "resume" callbacks and complete system transition.
* @state: PM transition of the system being carried out.
*
* Execute "resume" callbacks for all devices and complete the PM transition of
* the system.
*/
void dpm_resume_end(pm_message_t state)
{
might_sleep();
dpm_resume(state);
dpm_complete(state);
}
EXPORT_SYMBOL_GPL(dpm_resume_end);
/*------------------------- Suspend routines -------------------------*/
/**
* resume_event - Return a "resume" message for given "suspend" sleep state.
* @sleep_state: PM message representing a sleep state.
*
* Return a PM message representing the resume event corresponding to given
* sleep state.
*/
static pm_message_t resume_event(pm_message_t sleep_state)
{
switch (sleep_state.event) {
case PM_EVENT_SUSPEND:
return PMSG_RESUME;
case PM_EVENT_FREEZE:
case PM_EVENT_QUIESCE:
return PMSG_RECOVER;
case PM_EVENT_HIBERNATE:
return PMSG_RESTORE;
}
return PMSG_ON;
}
/**
* device_suspend_noirq - Execute a "late suspend" callback for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
*
* The driver of @dev will not receive interrupts while this function is being
* executed.
*/
static int device_suspend_noirq(struct device *dev, pm_message_t state)
{
int error = 0;
if (!dev->bus)
return 0;
if (dev->bus->pm) {
pm_dev_dbg(dev, state, "LATE ");
error = pm_noirq_op(dev, dev->bus->pm, state);
}
return error;
}
/**
* dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
* @state: PM transition of the system being carried out.
*
* Prevent device drivers from receiving interrupts and call the "noirq" suspend
* handlers for all non-sysdev devices.
*/
int dpm_suspend_noirq(pm_message_t state)
{
struct device *dev;
int error = 0;
suspend_device_irqs();
mutex_lock(&dpm_list_mtx);
list_for_each_entry_reverse(dev, &dpm_list, power.entry) {
error = device_suspend_noirq(dev, state);
if (error) {
pm_dev_err(dev, state, " late", error);
break;
}
dev->power.status = DPM_OFF_IRQ;
}
mutex_unlock(&dpm_list_mtx);
if (error)
dpm_resume_noirq(resume_event(state));
return error;
}
EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
/**
* device_suspend - Execute "suspend" callbacks for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
*/
static int device_suspend(struct device *dev, pm_message_t state)
{
int error = 0;
down(&dev->sem);
if (dev->class) {
if (dev->class->pm) {
pm_dev_dbg(dev, state, "class ");
error = pm_op(dev, dev->class->pm, state);
} else if (dev->class->suspend) {
pm_dev_dbg(dev, state, "legacy class ");
error = dev->class->suspend(dev, state);
suspend_report_result(dev->class->suspend, error);
}
if (error)
goto End;
}
if (dev->type) {
if (dev->type->pm) {
pm_dev_dbg(dev, state, "type ");
error = pm_op(dev, dev->type->pm, state);
}
if (error)
goto End;
}
if (dev->bus) {
if (dev->bus->pm) {
pm_dev_dbg(dev, state, "");
error = pm_op(dev, dev->bus->pm, state);
} else if (dev->bus->suspend) {
pm_dev_dbg(dev, state, "legacy ");
error = dev->bus->suspend(dev, state);
suspend_report_result(dev->bus->suspend, error);
}
}
End:
up(&dev->sem);
return error;
}
/**
* dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
* @state: PM transition of the system being carried out.
*/
static int dpm_suspend(pm_message_t state)
{
struct list_head list;
int error = 0;
INIT_LIST_HEAD(&list);
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_list)) {
struct device *dev = to_device(dpm_list.prev);
get_device(dev);
mutex_unlock(&dpm_list_mtx);
error = device_suspend(dev, state);
mutex_lock(&dpm_list_mtx);
if (error) {
pm_dev_err(dev, state, "", error);
put_device(dev);
break;
}
dev->power.status = DPM_OFF;
if (!list_empty(&dev->power.entry))
list_move(&dev->power.entry, &list);
put_device(dev);
}
list_splice(&list, dpm_list.prev);
mutex_unlock(&dpm_list_mtx);
return error;
}
/**
* device_prepare - Prepare a device for system power transition.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
*
* Execute the ->prepare() callback(s) for given device. No new children of the
* device may be registered after this function has returned.
*/
static int device_prepare(struct device *dev, pm_message_t state)
{
int error = 0;
down(&dev->sem);
if (dev->bus && dev->bus->pm && dev->bus->pm->prepare) {
pm_dev_dbg(dev, state, "preparing ");
error = dev->bus->pm->prepare(dev);
suspend_report_result(dev->bus->pm->prepare, error);
if (error)
goto End;
}
if (dev->type && dev->type->pm && dev->type->pm->prepare) {
pm_dev_dbg(dev, state, "preparing type ");
error = dev->type->pm->prepare(dev);
suspend_report_result(dev->type->pm->prepare, error);
if (error)
goto End;
}
if (dev->class && dev->class->pm && dev->class->pm->prepare) {
pm_dev_dbg(dev, state, "preparing class ");
error = dev->class->pm->prepare(dev);
suspend_report_result(dev->class->pm->prepare, error);
}
End:
up(&dev->sem);
return error;
}
/**
* dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
* @state: PM transition of the system being carried out.
*
* Execute the ->prepare() callback(s) for all devices.
*/
static int dpm_prepare(pm_message_t state)
{
struct list_head list;
int error = 0;
INIT_LIST_HEAD(&list);
mutex_lock(&dpm_list_mtx);
transition_started = true;
while (!list_empty(&dpm_list)) {
struct device *dev = to_device(dpm_list.next);
get_device(dev);
dev->power.status = DPM_PREPARING;
mutex_unlock(&dpm_list_mtx);
pm_runtime_get_noresume(dev);
if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) {
/* Wake-up requested during system sleep transition. */
pm_runtime_put_noidle(dev);
error = -EBUSY;
} else {
error = device_prepare(dev, state);
}
mutex_lock(&dpm_list_mtx);
if (error) {
dev->power.status = DPM_ON;
if (error == -EAGAIN) {
put_device(dev);
error = 0;
continue;
}
printk(KERN_ERR "PM: Failed to prepare device %s "
"for power transition: error %d\n",
kobject_name(&dev->kobj), error);
put_device(dev);
break;
}
dev->power.status = DPM_SUSPENDING;
if (!list_empty(&dev->power.entry))
list_move_tail(&dev->power.entry, &list);
put_device(dev);
}
list_splice(&list, &dpm_list);
mutex_unlock(&dpm_list_mtx);
return error;
}
/**
* dpm_suspend_start - Prepare devices for PM transition and suspend them.
* @state: PM transition of the system being carried out.
*
* Prepare all non-sysdev devices for system PM transition and execute "suspend"
* callbacks for them.
*/
int dpm_suspend_start(pm_message_t state)
{
int error;
might_sleep();
error = dpm_prepare(state);
if (!error)
error = dpm_suspend(state);
return error;
}
EXPORT_SYMBOL_GPL(dpm_suspend_start);
void __suspend_report_result(const char *function, void *fn, int ret)
{
if (ret)
printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
}
EXPORT_SYMBOL_GPL(__suspend_report_result);