blob: 42348e3589d3a55577182477d4711955223f156b (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
|
/*
* kernel/power/autosleep.c
*
* Opportunistic sleep support.
*
* Copyright (C) 2012 Rafael J. Wysocki <rjw@sisk.pl>
*/
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/pm_wakeup.h>
#include "power.h"
static suspend_state_t autosleep_state;
static struct workqueue_struct *autosleep_wq;
/*
* Note: it is only safe to mutex_lock(&autosleep_lock) if a wakeup_source
* is active, otherwise a deadlock with try_to_suspend() is possible.
* Alternatively mutex_lock_interruptible() can be used. This will then fail
* if an auto_sleep cycle tries to freeze processes.
*/
static DEFINE_MUTEX(autosleep_lock);
static struct wakeup_source *autosleep_ws;
static void try_to_suspend(struct work_struct *work)
{
unsigned int initial_count, final_count;
if (!pm_get_wakeup_count(&initial_count, true))
goto out;
mutex_lock(&autosleep_lock);
if (!pm_save_wakeup_count(initial_count)) {
mutex_unlock(&autosleep_lock);
goto out;
}
if (autosleep_state == PM_SUSPEND_ON) {
mutex_unlock(&autosleep_lock);
return;
}
if (autosleep_state >= PM_SUSPEND_MAX)
hibernate();
else
pm_suspend(autosleep_state);
mutex_unlock(&autosleep_lock);
if (!pm_get_wakeup_count(&final_count, false))
goto out;
/*
* If the wakeup occured for an unknown reason, wait to prevent the
* system from trying to suspend and waking up in a tight loop.
*/
if (final_count == initial_count)
schedule_timeout_uninterruptible(HZ / 2);
out:
queue_up_suspend_work();
}
static DECLARE_WORK(suspend_work, try_to_suspend);
void queue_up_suspend_work(void)
{
if (!work_pending(&suspend_work) && autosleep_state > PM_SUSPEND_ON)
queue_work(autosleep_wq, &suspend_work);
}
suspend_state_t pm_autosleep_state(void)
{
return autosleep_state;
}
int pm_autosleep_lock(void)
{
return mutex_lock_interruptible(&autosleep_lock);
}
void pm_autosleep_unlock(void)
{
mutex_unlock(&autosleep_lock);
}
int pm_autosleep_set_state(suspend_state_t state)
{
#ifndef CONFIG_HIBERNATION
if (state >= PM_SUSPEND_MAX)
return -EINVAL;
#endif
__pm_stay_awake(autosleep_ws);
mutex_lock(&autosleep_lock);
autosleep_state = state;
__pm_relax(autosleep_ws);
if (state > PM_SUSPEND_ON)
queue_up_suspend_work();
mutex_unlock(&autosleep_lock);
return 0;
}
int __init pm_autosleep_init(void)
{
autosleep_ws = wakeup_source_register("autosleep");
if (!autosleep_ws)
return -ENOMEM;
autosleep_wq = alloc_ordered_workqueue("autosleep", 0);
if (autosleep_wq)
return 0;
wakeup_source_unregister(autosleep_ws);
return -ENOMEM;
}
|
