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55716d26 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
a9d70523 RW |
2 | /* |
3 | * kernel/power/suspend_test.c - Suspend to RAM and standby test facility. | |
4 | * | |
5 | * Copyright (c) 2009 Pavel Machek <pavel@ucw.cz> | |
a9d70523 RW |
6 | */ |
7 | ||
8 | #include <linux/init.h> | |
9 | #include <linux/rtc.h> | |
10 | ||
11 | #include "power.h" | |
12 | ||
13 | /* | |
14 | * We test the system suspend code by setting an RTC wakealarm a short | |
15 | * time in the future, then suspending. Suspending the devices won't | |
16 | * normally take long ... some systems only need a few milliseconds. | |
17 | * | |
18 | * The time it takes is system-specific though, so when we test this | |
19 | * during system bootup we allow a LOT of time. | |
20 | */ | |
04bf7539 | 21 | #define TEST_SUSPEND_SECONDS 10 |
a9d70523 RW |
22 | |
23 | static unsigned long suspend_test_start_time; | |
2ce98689 SP |
24 | static u32 test_repeat_count_max = 1; |
25 | static u32 test_repeat_count_current; | |
a9d70523 RW |
26 | |
27 | void suspend_test_start(void) | |
28 | { | |
29 | /* FIXME Use better timebase than "jiffies", ideally a clocksource. | |
30 | * What we want is a hardware counter that will work correctly even | |
31 | * during the irqs-are-off stages of the suspend/resume cycle... | |
32 | */ | |
33 | suspend_test_start_time = jiffies; | |
34 | } | |
35 | ||
36 | void suspend_test_finish(const char *label) | |
37 | { | |
38 | long nj = jiffies - suspend_test_start_time; | |
39 | unsigned msec; | |
40 | ||
41 | msec = jiffies_to_msecs(abs(nj)); | |
42 | pr_info("PM: %s took %d.%03d seconds\n", label, | |
43 | msec / 1000, msec % 1000); | |
44 | ||
45 | /* Warning on suspend means the RTC alarm period needs to be | |
46 | * larger -- the system was sooo slooowwww to suspend that the | |
47 | * alarm (should have) fired before the system went to sleep! | |
48 | * | |
49 | * Warning on either suspend or resume also means the system | |
50 | * has some performance issues. The stack dump of a WARN_ON | |
51 | * is more likely to get the right attention than a printk... | |
52 | */ | |
04bf7539 RW |
53 | WARN(msec > (TEST_SUSPEND_SECONDS * 1000), |
54 | "Component: %s, time: %u\n", label, msec); | |
a9d70523 RW |
55 | } |
56 | ||
57 | /* | |
58 | * To test system suspend, we need a hands-off mechanism to resume the | |
59 | * system. RTCs wake alarms are a common self-contained mechanism. | |
60 | */ | |
61 | ||
62 | static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state) | |
63 | { | |
64 | static char err_readtime[] __initdata = | |
65 | KERN_ERR "PM: can't read %s time, err %d\n"; | |
66 | static char err_wakealarm [] __initdata = | |
67 | KERN_ERR "PM: can't set %s wakealarm, err %d\n"; | |
68 | static char err_suspend[] __initdata = | |
69 | KERN_ERR "PM: suspend test failed, error %d\n"; | |
70 | static char info_test[] __initdata = | |
71 | KERN_INFO "PM: test RTC wakeup from '%s' suspend\n"; | |
72 | ||
73 | unsigned long now; | |
74 | struct rtc_wkalrm alm; | |
75 | int status; | |
76 | ||
77 | /* this may fail if the RTC hasn't been initialized */ | |
2ce98689 | 78 | repeat: |
a9d70523 RW |
79 | status = rtc_read_time(rtc, &alm.time); |
80 | if (status < 0) { | |
81 | printk(err_readtime, dev_name(&rtc->dev), status); | |
82 | return; | |
83 | } | |
84 | rtc_tm_to_time(&alm.time, &now); | |
85 | ||
86 | memset(&alm, 0, sizeof alm); | |
87 | rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time); | |
88 | alm.enabled = true; | |
89 | ||
90 | status = rtc_set_alarm(rtc, &alm); | |
91 | if (status < 0) { | |
92 | printk(err_wakealarm, dev_name(&rtc->dev), status); | |
93 | return; | |
94 | } | |
95 | ||
96 | if (state == PM_SUSPEND_MEM) { | |
d431cbc5 | 97 | printk(info_test, pm_states[state]); |
a9d70523 RW |
98 | status = pm_suspend(state); |
99 | if (status == -ENODEV) | |
100 | state = PM_SUSPEND_STANDBY; | |
101 | } | |
102 | if (state == PM_SUSPEND_STANDBY) { | |
d431cbc5 | 103 | printk(info_test, pm_states[state]); |
a9d70523 | 104 | status = pm_suspend(state); |
bc7115b1 | 105 | if (status < 0) |
690cbb90 | 106 | state = PM_SUSPEND_TO_IDLE; |
a9d70523 | 107 | } |
690cbb90 | 108 | if (state == PM_SUSPEND_TO_IDLE) { |
bc7115b1 SP |
109 | printk(info_test, pm_states[state]); |
110 | status = pm_suspend(state); | |
111 | } | |
112 | ||
a9d70523 RW |
113 | if (status < 0) |
114 | printk(err_suspend, status); | |
115 | ||
2ce98689 SP |
116 | test_repeat_count_current++; |
117 | if (test_repeat_count_current < test_repeat_count_max) | |
118 | goto repeat; | |
119 | ||
a9d70523 RW |
120 | /* Some platforms can't detect that the alarm triggered the |
121 | * wakeup, or (accordingly) disable it after it afterwards. | |
122 | * It's supposed to give oneshot behavior; cope. | |
123 | */ | |
124 | alm.enabled = false; | |
125 | rtc_set_alarm(rtc, &alm); | |
126 | } | |
127 | ||
9f3b795a | 128 | static int __init has_wakealarm(struct device *dev, const void *data) |
a9d70523 RW |
129 | { |
130 | struct rtc_device *candidate = to_rtc_device(dev); | |
131 | ||
132 | if (!candidate->ops->set_alarm) | |
133 | return 0; | |
134 | if (!device_may_wakeup(candidate->dev.parent)) | |
135 | return 0; | |
136 | ||
a9d70523 RW |
137 | return 1; |
138 | } | |
139 | ||
140 | /* | |
141 | * Kernel options like "test_suspend=mem" force suspend/resume sanity tests | |
142 | * at startup time. They're normally disabled, for faster boot and because | |
143 | * we can't know which states really work on this particular system. | |
144 | */ | |
62109b43 | 145 | static const char *test_state_label __initdata; |
a9d70523 RW |
146 | |
147 | static char warn_bad_state[] __initdata = | |
148 | KERN_WARNING "PM: can't test '%s' suspend state\n"; | |
149 | ||
150 | static int __init setup_test_suspend(char *value) | |
151 | { | |
62109b43 | 152 | int i; |
2ce98689 SP |
153 | char *repeat; |
154 | char *suspend_type; | |
a9d70523 | 155 | |
2ce98689 | 156 | /* example : "=mem[,N]" ==> "mem[,N]" */ |
a9d70523 | 157 | value++; |
2ce98689 SP |
158 | suspend_type = strsep(&value, ","); |
159 | if (!suspend_type) | |
160 | return 0; | |
161 | ||
162 | repeat = strsep(&value, ","); | |
163 | if (repeat) { | |
164 | if (kstrtou32(repeat, 0, &test_repeat_count_max)) | |
165 | return 0; | |
166 | } | |
167 | ||
8cff6679 | 168 | for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) |
2ce98689 | 169 | if (!strcmp(pm_labels[i], suspend_type)) { |
62109b43 | 170 | test_state_label = pm_labels[i]; |
27ddcc65 RW |
171 | return 0; |
172 | } | |
173 | ||
2ce98689 | 174 | printk(warn_bad_state, suspend_type); |
a9d70523 RW |
175 | return 0; |
176 | } | |
177 | __setup("test_suspend", setup_test_suspend); | |
178 | ||
179 | static int __init test_suspend(void) | |
180 | { | |
181 | static char warn_no_rtc[] __initdata = | |
182 | KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n"; | |
183 | ||
a9d70523 | 184 | struct rtc_device *rtc = NULL; |
9f3b795a | 185 | struct device *dev; |
62109b43 | 186 | suspend_state_t test_state; |
a9d70523 RW |
187 | |
188 | /* PM is initialized by now; is that state testable? */ | |
62109b43 RW |
189 | if (!test_state_label) |
190 | return 0; | |
191 | ||
192 | for (test_state = PM_SUSPEND_MIN; test_state < PM_SUSPEND_MAX; test_state++) { | |
193 | const char *state_label = pm_states[test_state]; | |
194 | ||
195 | if (state_label && !strcmp(test_state_label, state_label)) | |
196 | break; | |
197 | } | |
198 | if (test_state == PM_SUSPEND_MAX) { | |
199 | printk(warn_bad_state, test_state_label); | |
200 | return 0; | |
a9d70523 RW |
201 | } |
202 | ||
203 | /* RTCs have initialized by now too ... can we use one? */ | |
9f3b795a | 204 | dev = class_find_device(rtc_class, NULL, NULL, has_wakealarm); |
ceb75787 | 205 | if (dev) { |
9f3b795a | 206 | rtc = rtc_class_open(dev_name(dev)); |
ceb75787 JH |
207 | put_device(dev); |
208 | } | |
a9d70523 RW |
209 | if (!rtc) { |
210 | printk(warn_no_rtc); | |
62109b43 | 211 | return 0; |
a9d70523 RW |
212 | } |
213 | ||
214 | /* go for it */ | |
215 | test_wakealarm(rtc, test_state); | |
216 | rtc_class_close(rtc); | |
a9d70523 RW |
217 | return 0; |
218 | } | |
219 | late_initcall(test_suspend); |