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a9d70523 RW |
1 | /* |
2 | * kernel/power/suspend_test.c - Suspend to RAM and standby test facility. | |
3 | * | |
4 | * Copyright (c) 2009 Pavel Machek <pavel@ucw.cz> | |
5 | * | |
6 | * This file is released under the GPLv2. | |
7 | */ | |
8 | ||
9 | #include <linux/init.h> | |
10 | #include <linux/rtc.h> | |
11 | ||
12 | #include "power.h" | |
13 | ||
14 | /* | |
15 | * We test the system suspend code by setting an RTC wakealarm a short | |
16 | * time in the future, then suspending. Suspending the devices won't | |
17 | * normally take long ... some systems only need a few milliseconds. | |
18 | * | |
19 | * The time it takes is system-specific though, so when we test this | |
20 | * during system bootup we allow a LOT of time. | |
21 | */ | |
04bf7539 | 22 | #define TEST_SUSPEND_SECONDS 10 |
a9d70523 RW |
23 | |
24 | static unsigned long suspend_test_start_time; | |
2ce98689 SP |
25 | static u32 test_repeat_count_max = 1; |
26 | static u32 test_repeat_count_current; | |
a9d70523 RW |
27 | |
28 | void suspend_test_start(void) | |
29 | { | |
30 | /* FIXME Use better timebase than "jiffies", ideally a clocksource. | |
31 | * What we want is a hardware counter that will work correctly even | |
32 | * during the irqs-are-off stages of the suspend/resume cycle... | |
33 | */ | |
34 | suspend_test_start_time = jiffies; | |
35 | } | |
36 | ||
37 | void suspend_test_finish(const char *label) | |
38 | { | |
39 | long nj = jiffies - suspend_test_start_time; | |
40 | unsigned msec; | |
41 | ||
42 | msec = jiffies_to_msecs(abs(nj)); | |
43 | pr_info("PM: %s took %d.%03d seconds\n", label, | |
44 | msec / 1000, msec % 1000); | |
45 | ||
46 | /* Warning on suspend means the RTC alarm period needs to be | |
47 | * larger -- the system was sooo slooowwww to suspend that the | |
48 | * alarm (should have) fired before the system went to sleep! | |
49 | * | |
50 | * Warning on either suspend or resume also means the system | |
51 | * has some performance issues. The stack dump of a WARN_ON | |
52 | * is more likely to get the right attention than a printk... | |
53 | */ | |
04bf7539 RW |
54 | WARN(msec > (TEST_SUSPEND_SECONDS * 1000), |
55 | "Component: %s, time: %u\n", label, msec); | |
a9d70523 RW |
56 | } |
57 | ||
58 | /* | |
59 | * To test system suspend, we need a hands-off mechanism to resume the | |
60 | * system. RTCs wake alarms are a common self-contained mechanism. | |
61 | */ | |
62 | ||
63 | static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state) | |
64 | { | |
65 | static char err_readtime[] __initdata = | |
66 | KERN_ERR "PM: can't read %s time, err %d\n"; | |
67 | static char err_wakealarm [] __initdata = | |
68 | KERN_ERR "PM: can't set %s wakealarm, err %d\n"; | |
69 | static char err_suspend[] __initdata = | |
70 | KERN_ERR "PM: suspend test failed, error %d\n"; | |
71 | static char info_test[] __initdata = | |
72 | KERN_INFO "PM: test RTC wakeup from '%s' suspend\n"; | |
73 | ||
74 | unsigned long now; | |
75 | struct rtc_wkalrm alm; | |
76 | int status; | |
77 | ||
78 | /* this may fail if the RTC hasn't been initialized */ | |
2ce98689 | 79 | repeat: |
a9d70523 RW |
80 | status = rtc_read_time(rtc, &alm.time); |
81 | if (status < 0) { | |
82 | printk(err_readtime, dev_name(&rtc->dev), status); | |
83 | return; | |
84 | } | |
85 | rtc_tm_to_time(&alm.time, &now); | |
86 | ||
87 | memset(&alm, 0, sizeof alm); | |
88 | rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time); | |
89 | alm.enabled = true; | |
90 | ||
91 | status = rtc_set_alarm(rtc, &alm); | |
92 | if (status < 0) { | |
93 | printk(err_wakealarm, dev_name(&rtc->dev), status); | |
94 | return; | |
95 | } | |
96 | ||
97 | if (state == PM_SUSPEND_MEM) { | |
d431cbc5 | 98 | printk(info_test, pm_states[state]); |
a9d70523 RW |
99 | status = pm_suspend(state); |
100 | if (status == -ENODEV) | |
101 | state = PM_SUSPEND_STANDBY; | |
102 | } | |
103 | if (state == PM_SUSPEND_STANDBY) { | |
d431cbc5 | 104 | printk(info_test, pm_states[state]); |
a9d70523 | 105 | status = pm_suspend(state); |
bc7115b1 SP |
106 | if (status < 0) |
107 | state = PM_SUSPEND_FREEZE; | |
a9d70523 | 108 | } |
bc7115b1 SP |
109 | if (state == PM_SUSPEND_FREEZE) { |
110 | printk(info_test, pm_states[state]); | |
111 | status = pm_suspend(state); | |
112 | } | |
113 | ||
a9d70523 RW |
114 | if (status < 0) |
115 | printk(err_suspend, status); | |
116 | ||
2ce98689 SP |
117 | test_repeat_count_current++; |
118 | if (test_repeat_count_current < test_repeat_count_max) | |
119 | goto repeat; | |
120 | ||
a9d70523 RW |
121 | /* Some platforms can't detect that the alarm triggered the |
122 | * wakeup, or (accordingly) disable it after it afterwards. | |
123 | * It's supposed to give oneshot behavior; cope. | |
124 | */ | |
125 | alm.enabled = false; | |
126 | rtc_set_alarm(rtc, &alm); | |
127 | } | |
128 | ||
9f3b795a | 129 | static int __init has_wakealarm(struct device *dev, const void *data) |
a9d70523 RW |
130 | { |
131 | struct rtc_device *candidate = to_rtc_device(dev); | |
132 | ||
133 | if (!candidate->ops->set_alarm) | |
134 | return 0; | |
135 | if (!device_may_wakeup(candidate->dev.parent)) | |
136 | return 0; | |
137 | ||
a9d70523 RW |
138 | return 1; |
139 | } | |
140 | ||
141 | /* | |
142 | * Kernel options like "test_suspend=mem" force suspend/resume sanity tests | |
143 | * at startup time. They're normally disabled, for faster boot and because | |
144 | * we can't know which states really work on this particular system. | |
145 | */ | |
62109b43 | 146 | static const char *test_state_label __initdata; |
a9d70523 RW |
147 | |
148 | static char warn_bad_state[] __initdata = | |
149 | KERN_WARNING "PM: can't test '%s' suspend state\n"; | |
150 | ||
151 | static int __init setup_test_suspend(char *value) | |
152 | { | |
62109b43 | 153 | int i; |
2ce98689 SP |
154 | char *repeat; |
155 | char *suspend_type; | |
a9d70523 | 156 | |
2ce98689 | 157 | /* example : "=mem[,N]" ==> "mem[,N]" */ |
a9d70523 | 158 | value++; |
2ce98689 SP |
159 | suspend_type = strsep(&value, ","); |
160 | if (!suspend_type) | |
161 | return 0; | |
162 | ||
163 | repeat = strsep(&value, ","); | |
164 | if (repeat) { | |
165 | if (kstrtou32(repeat, 0, &test_repeat_count_max)) | |
166 | return 0; | |
167 | } | |
168 | ||
62109b43 | 169 | for (i = 0; pm_labels[i]; i++) |
2ce98689 | 170 | if (!strcmp(pm_labels[i], suspend_type)) { |
62109b43 | 171 | test_state_label = pm_labels[i]; |
27ddcc65 RW |
172 | return 0; |
173 | } | |
174 | ||
2ce98689 | 175 | printk(warn_bad_state, suspend_type); |
a9d70523 RW |
176 | return 0; |
177 | } | |
178 | __setup("test_suspend", setup_test_suspend); | |
179 | ||
180 | static int __init test_suspend(void) | |
181 | { | |
182 | static char warn_no_rtc[] __initdata = | |
183 | KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n"; | |
184 | ||
a9d70523 | 185 | struct rtc_device *rtc = NULL; |
9f3b795a | 186 | struct device *dev; |
62109b43 | 187 | suspend_state_t test_state; |
a9d70523 RW |
188 | |
189 | /* PM is initialized by now; is that state testable? */ | |
62109b43 RW |
190 | if (!test_state_label) |
191 | return 0; | |
192 | ||
193 | for (test_state = PM_SUSPEND_MIN; test_state < PM_SUSPEND_MAX; test_state++) { | |
194 | const char *state_label = pm_states[test_state]; | |
195 | ||
196 | if (state_label && !strcmp(test_state_label, state_label)) | |
197 | break; | |
198 | } | |
199 | if (test_state == PM_SUSPEND_MAX) { | |
200 | printk(warn_bad_state, test_state_label); | |
201 | return 0; | |
a9d70523 RW |
202 | } |
203 | ||
204 | /* RTCs have initialized by now too ... can we use one? */ | |
9f3b795a MM |
205 | dev = class_find_device(rtc_class, NULL, NULL, has_wakealarm); |
206 | if (dev) | |
207 | rtc = rtc_class_open(dev_name(dev)); | |
a9d70523 RW |
208 | if (!rtc) { |
209 | printk(warn_no_rtc); | |
62109b43 | 210 | return 0; |
a9d70523 RW |
211 | } |
212 | ||
213 | /* go for it */ | |
214 | test_wakealarm(rtc, test_state); | |
215 | rtc_class_close(rtc); | |
a9d70523 RW |
216 | return 0; |
217 | } | |
218 | late_initcall(test_suspend); |