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Diffstat (limited to 'drivers/base/power/main.c')
-rw-r--r--drivers/base/power/main.c163
1 files changed, 142 insertions, 21 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index a5142bddef4..d477f4dc5e5 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -25,6 +25,7 @@
#include <linux/resume-trace.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
+#include <linux/async.h>
#include "../base.h"
#include "power.h"
@@ -34,14 +35,15 @@
* 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
+ * Since device_pm_add() may be called with a device lock held,
+ * we must never try to acquire a device lock while holding
* dpm_list_mutex.
*/
LIST_HEAD(dpm_list);
static DEFINE_MUTEX(dpm_list_mtx);
+static pm_message_t pm_transition;
/*
* Set once the preparation of devices for a PM transition has started, reset
@@ -56,6 +58,7 @@ static bool transition_started;
void device_pm_init(struct device *dev)
{
dev->power.status = DPM_ON;
+ init_completion(&dev->power.completion);
pm_runtime_init(dev);
}
@@ -111,6 +114,7 @@ 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));
+ complete_all(&dev->power.completion);
mutex_lock(&dpm_list_mtx);
list_del_init(&dev->power.entry);
mutex_unlock(&dpm_list_mtx);
@@ -188,6 +192,31 @@ static void initcall_debug_report(struct device *dev, ktime_t calltime,
}
/**
+ * dpm_wait - Wait for a PM operation to complete.
+ * @dev: Device to wait for.
+ * @async: If unset, wait only if the device's power.async_suspend flag is set.
+ */
+static void dpm_wait(struct device *dev, bool async)
+{
+ if (!dev)
+ return;
+
+ if (async || (pm_async_enabled && dev->power.async_suspend))
+ wait_for_completion(&dev->power.completion);
+}
+
+static int dpm_wait_fn(struct device *dev, void *async_ptr)
+{
+ dpm_wait(dev, *((bool *)async_ptr));
+ return 0;
+}
+
+static void dpm_wait_for_children(struct device *dev, bool async)
+{
+ device_for_each_child(dev, &async, dpm_wait_fn);
+}
+
+/**
* pm_op - Execute the PM operation appropriate for given PM event.
* @dev: Device to handle.
* @ops: PM operations to choose from.
@@ -271,8 +300,9 @@ static int pm_noirq_op(struct device *dev,
ktime_t calltime, delta, rettime;
if (initcall_debug) {
- pr_info("calling %s_i+ @ %i\n",
- dev_name(dev), task_pid_nr(current));
+ pr_info("calling %s+ @ %i, parent: %s\n",
+ dev_name(dev), task_pid_nr(current),
+ dev->parent ? dev_name(dev->parent) : "none");
calltime = ktime_get();
}
@@ -468,15 +498,19 @@ static int legacy_resume(struct device *dev, int (*cb)(struct device *dev))
* device_resume - Execute "resume" callbacks for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
+ * @async: If true, the device is being resumed asynchronously.
*/
-static int device_resume(struct device *dev, pm_message_t state)
+static int device_resume(struct device *dev, pm_message_t state, bool async)
{
int error = 0;
TRACE_DEVICE(dev);
TRACE_RESUME(0);
- down(&dev->sem);
+ dpm_wait(dev->parent, async);
+ device_lock(dev);
+
+ dev->power.status = DPM_RESUMING;
if (dev->bus) {
if (dev->bus->pm) {
@@ -509,12 +543,30 @@ static int device_resume(struct device *dev, pm_message_t state)
}
}
End:
- up(&dev->sem);
+ device_unlock(dev);
+ complete_all(&dev->power.completion);
TRACE_RESUME(error);
return error;
}
+static void async_resume(void *data, async_cookie_t cookie)
+{
+ struct device *dev = (struct device *)data;
+ int error;
+
+ error = device_resume(dev, pm_transition, true);
+ if (error)
+ pm_dev_err(dev, pm_transition, " async", error);
+ put_device(dev);
+}
+
+static bool is_async(struct device *dev)
+{
+ return dev->power.async_suspend && pm_async_enabled
+ && !pm_trace_is_enabled();
+}
+
/**
* dpm_resume - Execute "resume" callbacks for non-sysdev devices.
* @state: PM transition of the system being carried out.
@@ -525,21 +577,33 @@ static int device_resume(struct device *dev, pm_message_t state)
static void dpm_resume(pm_message_t state)
{
struct list_head list;
+ struct device *dev;
ktime_t starttime = ktime_get();
INIT_LIST_HEAD(&list);
mutex_lock(&dpm_list_mtx);
- while (!list_empty(&dpm_list)) {
- struct device *dev = to_device(dpm_list.next);
+ pm_transition = state;
+
+ list_for_each_entry(dev, &dpm_list, power.entry) {
+ if (dev->power.status < DPM_OFF)
+ continue;
+
+ INIT_COMPLETION(dev->power.completion);
+ if (is_async(dev)) {
+ get_device(dev);
+ async_schedule(async_resume, dev);
+ }
+ }
+ while (!list_empty(&dpm_list)) {
+ dev = to_device(dpm_list.next);
get_device(dev);
- if (dev->power.status >= DPM_OFF) {
+ if (dev->power.status >= DPM_OFF && !is_async(dev)) {
int error;
- dev->power.status = DPM_RESUMING;
mutex_unlock(&dpm_list_mtx);
- error = device_resume(dev, state);
+ error = device_resume(dev, state, false);
mutex_lock(&dpm_list_mtx);
if (error)
@@ -554,6 +618,7 @@ static void dpm_resume(pm_message_t state)
}
list_splice(&list, &dpm_list);
mutex_unlock(&dpm_list_mtx);
+ async_synchronize_full();
dpm_show_time(starttime, state, NULL);
}
@@ -564,7 +629,7 @@ static void dpm_resume(pm_message_t state)
*/
static void device_complete(struct device *dev, pm_message_t state)
{
- down(&dev->sem);
+ device_lock(dev);
if (dev->class && dev->class->pm && dev->class->pm->complete) {
pm_dev_dbg(dev, state, "completing class ");
@@ -581,7 +646,7 @@ static void device_complete(struct device *dev, pm_message_t state)
dev->bus->pm->complete(dev);
}
- up(&dev->sem);
+ device_unlock(dev);
}
/**
@@ -731,16 +796,23 @@ static int legacy_suspend(struct device *dev, pm_message_t state,
return error;
}
+static int async_error;
+
/**
* device_suspend - Execute "suspend" callbacks for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
+ * @async: If true, the device is being suspended asynchronously.
*/
-static int device_suspend(struct device *dev, pm_message_t state)
+static int __device_suspend(struct device *dev, pm_message_t state, bool async)
{
int error = 0;
- down(&dev->sem);
+ dpm_wait_for_children(dev, async);
+ device_lock(dev);
+
+ if (async_error)
+ goto End;
if (dev->class) {
if (dev->class->pm) {
@@ -772,12 +844,44 @@ static int device_suspend(struct device *dev, pm_message_t state)
error = legacy_suspend(dev, state, dev->bus->suspend);
}
}
+
+ if (!error)
+ dev->power.status = DPM_OFF;
+
End:
- up(&dev->sem);
+ device_unlock(dev);
+ complete_all(&dev->power.completion);
return error;
}
+static void async_suspend(void *data, async_cookie_t cookie)
+{
+ struct device *dev = (struct device *)data;
+ int error;
+
+ error = __device_suspend(dev, pm_transition, true);
+ if (error) {
+ pm_dev_err(dev, pm_transition, " async", error);
+ async_error = error;
+ }
+
+ put_device(dev);
+}
+
+static int device_suspend(struct device *dev)
+{
+ INIT_COMPLETION(dev->power.completion);
+
+ if (pm_async_enabled && dev->power.async_suspend) {
+ get_device(dev);
+ async_schedule(async_suspend, dev);
+ return 0;
+ }
+
+ return __device_suspend(dev, pm_transition, false);
+}
+
/**
* dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
* @state: PM transition of the system being carried out.
@@ -790,13 +894,15 @@ static int dpm_suspend(pm_message_t state)
INIT_LIST_HEAD(&list);
mutex_lock(&dpm_list_mtx);
+ pm_transition = state;
+ async_error = 0;
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);
+ error = device_suspend(dev);
mutex_lock(&dpm_list_mtx);
if (error) {
@@ -804,13 +910,17 @@ static int dpm_suspend(pm_message_t state)
put_device(dev);
break;
}
- dev->power.status = DPM_OFF;
if (!list_empty(&dev->power.entry))
list_move(&dev->power.entry, &list);
put_device(dev);
+ if (async_error)
+ break;
}
list_splice(&list, dpm_list.prev);
mutex_unlock(&dpm_list_mtx);
+ async_synchronize_full();
+ if (!error)
+ error = async_error;
if (!error)
dpm_show_time(starttime, state, NULL);
return error;
@@ -828,7 +938,7 @@ static int device_prepare(struct device *dev, pm_message_t state)
{
int error = 0;
- down(&dev->sem);
+ device_lock(dev);
if (dev->bus && dev->bus->pm && dev->bus->pm->prepare) {
pm_dev_dbg(dev, state, "preparing ");
@@ -852,7 +962,7 @@ static int device_prepare(struct device *dev, pm_message_t state)
suspend_report_result(dev->class->pm->prepare, error);
}
End:
- up(&dev->sem);
+ device_unlock(dev);
return error;
}
@@ -936,3 +1046,14 @@ void __suspend_report_result(const char *function, void *fn, int ret)
printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
}
EXPORT_SYMBOL_GPL(__suspend_report_result);
+
+/**
+ * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
+ * @dev: Device to wait for.
+ * @subordinate: Device that needs to wait for @dev.
+ */
+void device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
+{
+ dpm_wait(dev, subordinate->power.async_suspend);
+}
+EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);