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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 | */ | |
22 | #define TEST_SUSPEND_SECONDS 5 | |
23 | ||
24 | static unsigned long suspend_test_start_time; | |
25 | ||
26 | void suspend_test_start(void) | |
27 | { | |
28 | /* FIXME Use better timebase than "jiffies", ideally a clocksource. | |
29 | * What we want is a hardware counter that will work correctly even | |
30 | * during the irqs-are-off stages of the suspend/resume cycle... | |
31 | */ | |
32 | suspend_test_start_time = jiffies; | |
33 | } | |
34 | ||
35 | void suspend_test_finish(const char *label) | |
36 | { | |
37 | long nj = jiffies - suspend_test_start_time; | |
38 | unsigned msec; | |
39 | ||
40 | msec = jiffies_to_msecs(abs(nj)); | |
41 | pr_info("PM: %s took %d.%03d seconds\n", label, | |
42 | msec / 1000, msec % 1000); | |
43 | ||
44 | /* Warning on suspend means the RTC alarm period needs to be | |
45 | * larger -- the system was sooo slooowwww to suspend that the | |
46 | * alarm (should have) fired before the system went to sleep! | |
47 | * | |
48 | * Warning on either suspend or resume also means the system | |
49 | * has some performance issues. The stack dump of a WARN_ON | |
50 | * is more likely to get the right attention than a printk... | |
51 | */ | |
52 | WARN(msec > (TEST_SUSPEND_SECONDS * 1000), "Component: %s\n", label); | |
53 | } | |
54 | ||
55 | /* | |
56 | * To test system suspend, we need a hands-off mechanism to resume the | |
57 | * system. RTCs wake alarms are a common self-contained mechanism. | |
58 | */ | |
59 | ||
60 | static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state) | |
61 | { | |
62 | static char err_readtime[] __initdata = | |
63 | KERN_ERR "PM: can't read %s time, err %d\n"; | |
64 | static char err_wakealarm [] __initdata = | |
65 | KERN_ERR "PM: can't set %s wakealarm, err %d\n"; | |
66 | static char err_suspend[] __initdata = | |
67 | KERN_ERR "PM: suspend test failed, error %d\n"; | |
68 | static char info_test[] __initdata = | |
69 | KERN_INFO "PM: test RTC wakeup from '%s' suspend\n"; | |
70 | ||
71 | unsigned long now; | |
72 | struct rtc_wkalrm alm; | |
73 | int status; | |
74 | ||
75 | /* this may fail if the RTC hasn't been initialized */ | |
76 | status = rtc_read_time(rtc, &alm.time); | |
77 | if (status < 0) { | |
78 | printk(err_readtime, dev_name(&rtc->dev), status); | |
79 | return; | |
80 | } | |
81 | rtc_tm_to_time(&alm.time, &now); | |
82 | ||
83 | memset(&alm, 0, sizeof alm); | |
84 | rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time); | |
85 | alm.enabled = true; | |
86 | ||
87 | status = rtc_set_alarm(rtc, &alm); | |
88 | if (status < 0) { | |
89 | printk(err_wakealarm, dev_name(&rtc->dev), status); | |
90 | return; | |
91 | } | |
92 | ||
93 | if (state == PM_SUSPEND_MEM) { | |
94 | printk(info_test, pm_states[state]); | |
95 | status = pm_suspend(state); | |
96 | if (status == -ENODEV) | |
97 | state = PM_SUSPEND_STANDBY; | |
98 | } | |
99 | if (state == PM_SUSPEND_STANDBY) { | |
100 | printk(info_test, pm_states[state]); | |
101 | status = pm_suspend(state); | |
102 | } | |
103 | if (status < 0) | |
104 | printk(err_suspend, status); | |
105 | ||
106 | /* Some platforms can't detect that the alarm triggered the | |
107 | * wakeup, or (accordingly) disable it after it afterwards. | |
108 | * It's supposed to give oneshot behavior; cope. | |
109 | */ | |
110 | alm.enabled = false; | |
111 | rtc_set_alarm(rtc, &alm); | |
112 | } | |
113 | ||
114 | static int __init has_wakealarm(struct device *dev, void *name_ptr) | |
115 | { | |
116 | struct rtc_device *candidate = to_rtc_device(dev); | |
117 | ||
118 | if (!candidate->ops->set_alarm) | |
119 | return 0; | |
120 | if (!device_may_wakeup(candidate->dev.parent)) | |
121 | return 0; | |
122 | ||
123 | *(const char **)name_ptr = dev_name(dev); | |
124 | return 1; | |
125 | } | |
126 | ||
127 | /* | |
128 | * Kernel options like "test_suspend=mem" force suspend/resume sanity tests | |
129 | * at startup time. They're normally disabled, for faster boot and because | |
130 | * we can't know which states really work on this particular system. | |
131 | */ | |
132 | static suspend_state_t test_state __initdata = PM_SUSPEND_ON; | |
133 | ||
134 | static char warn_bad_state[] __initdata = | |
135 | KERN_WARNING "PM: can't test '%s' suspend state\n"; | |
136 | ||
137 | static int __init setup_test_suspend(char *value) | |
138 | { | |
139 | unsigned i; | |
140 | ||
141 | /* "=mem" ==> "mem" */ | |
142 | value++; | |
143 | for (i = 0; i < PM_SUSPEND_MAX; i++) { | |
144 | if (!pm_states[i]) | |
145 | continue; | |
146 | if (strcmp(pm_states[i], value) != 0) | |
147 | continue; | |
148 | test_state = (__force suspend_state_t) i; | |
149 | return 0; | |
150 | } | |
151 | printk(warn_bad_state, value); | |
152 | return 0; | |
153 | } | |
154 | __setup("test_suspend", setup_test_suspend); | |
155 | ||
156 | static int __init test_suspend(void) | |
157 | { | |
158 | static char warn_no_rtc[] __initdata = | |
159 | KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n"; | |
160 | ||
161 | char *pony = NULL; | |
162 | struct rtc_device *rtc = NULL; | |
163 | ||
164 | /* PM is initialized by now; is that state testable? */ | |
165 | if (test_state == PM_SUSPEND_ON) | |
166 | goto done; | |
167 | if (!valid_state(test_state)) { | |
168 | printk(warn_bad_state, pm_states[test_state]); | |
169 | goto done; | |
170 | } | |
171 | ||
172 | /* RTCs have initialized by now too ... can we use one? */ | |
173 | class_find_device(rtc_class, NULL, &pony, has_wakealarm); | |
174 | if (pony) | |
175 | rtc = rtc_class_open(pony); | |
176 | if (!rtc) { | |
177 | printk(warn_no_rtc); | |
178 | goto done; | |
179 | } | |
180 | ||
181 | /* go for it */ | |
182 | test_wakealarm(rtc, test_state); | |
183 | rtc_class_close(rtc); | |
184 | done: | |
185 | return 0; | |
186 | } | |
187 | late_initcall(test_suspend); |