1a9d70523SRafael J. Wysocki /* 2a9d70523SRafael J. Wysocki * kernel/power/suspend_test.c - Suspend to RAM and standby test facility. 3a9d70523SRafael J. Wysocki * 4a9d70523SRafael J. Wysocki * Copyright (c) 2009 Pavel Machek <pavel@ucw.cz> 5a9d70523SRafael J. Wysocki * 6a9d70523SRafael J. Wysocki * This file is released under the GPLv2. 7a9d70523SRafael J. Wysocki */ 8a9d70523SRafael J. Wysocki 9a9d70523SRafael J. Wysocki #include <linux/init.h> 10a9d70523SRafael J. Wysocki #include <linux/rtc.h> 11a9d70523SRafael J. Wysocki 12a9d70523SRafael J. Wysocki #include "power.h" 13a9d70523SRafael J. Wysocki 14a9d70523SRafael J. Wysocki /* 15a9d70523SRafael J. Wysocki * We test the system suspend code by setting an RTC wakealarm a short 16a9d70523SRafael J. Wysocki * time in the future, then suspending. Suspending the devices won't 17a9d70523SRafael J. Wysocki * normally take long ... some systems only need a few milliseconds. 18a9d70523SRafael J. Wysocki * 19a9d70523SRafael J. Wysocki * The time it takes is system-specific though, so when we test this 20a9d70523SRafael J. Wysocki * during system bootup we allow a LOT of time. 21a9d70523SRafael J. Wysocki */ 2204bf7539SRafael J. Wysocki #define TEST_SUSPEND_SECONDS 10 23a9d70523SRafael J. Wysocki 24a9d70523SRafael J. Wysocki static unsigned long suspend_test_start_time; 25a9d70523SRafael J. Wysocki 26a9d70523SRafael J. Wysocki void suspend_test_start(void) 27a9d70523SRafael J. Wysocki { 28a9d70523SRafael J. Wysocki /* FIXME Use better timebase than "jiffies", ideally a clocksource. 29a9d70523SRafael J. Wysocki * What we want is a hardware counter that will work correctly even 30a9d70523SRafael J. Wysocki * during the irqs-are-off stages of the suspend/resume cycle... 31a9d70523SRafael J. Wysocki */ 32a9d70523SRafael J. Wysocki suspend_test_start_time = jiffies; 33a9d70523SRafael J. Wysocki } 34a9d70523SRafael J. Wysocki 35a9d70523SRafael J. Wysocki void suspend_test_finish(const char *label) 36a9d70523SRafael J. Wysocki { 37a9d70523SRafael J. Wysocki long nj = jiffies - suspend_test_start_time; 38a9d70523SRafael J. Wysocki unsigned msec; 39a9d70523SRafael J. Wysocki 40a9d70523SRafael J. Wysocki msec = jiffies_to_msecs(abs(nj)); 41a9d70523SRafael J. Wysocki pr_info("PM: %s took %d.%03d seconds\n", label, 42a9d70523SRafael J. Wysocki msec / 1000, msec % 1000); 43a9d70523SRafael J. Wysocki 44a9d70523SRafael J. Wysocki /* Warning on suspend means the RTC alarm period needs to be 45a9d70523SRafael J. Wysocki * larger -- the system was sooo slooowwww to suspend that the 46a9d70523SRafael J. Wysocki * alarm (should have) fired before the system went to sleep! 47a9d70523SRafael J. Wysocki * 48a9d70523SRafael J. Wysocki * Warning on either suspend or resume also means the system 49a9d70523SRafael J. Wysocki * has some performance issues. The stack dump of a WARN_ON 50a9d70523SRafael J. Wysocki * is more likely to get the right attention than a printk... 51a9d70523SRafael J. Wysocki */ 5204bf7539SRafael J. Wysocki WARN(msec > (TEST_SUSPEND_SECONDS * 1000), 5304bf7539SRafael J. Wysocki "Component: %s, time: %u\n", label, msec); 54a9d70523SRafael J. Wysocki } 55a9d70523SRafael J. Wysocki 56a9d70523SRafael J. Wysocki /* 57a9d70523SRafael J. Wysocki * To test system suspend, we need a hands-off mechanism to resume the 58a9d70523SRafael J. Wysocki * system. RTCs wake alarms are a common self-contained mechanism. 59a9d70523SRafael J. Wysocki */ 60a9d70523SRafael J. Wysocki 61a9d70523SRafael J. Wysocki static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state) 62a9d70523SRafael J. Wysocki { 63a9d70523SRafael J. Wysocki static char err_readtime[] __initdata = 64a9d70523SRafael J. Wysocki KERN_ERR "PM: can't read %s time, err %d\n"; 65a9d70523SRafael J. Wysocki static char err_wakealarm [] __initdata = 66a9d70523SRafael J. Wysocki KERN_ERR "PM: can't set %s wakealarm, err %d\n"; 67a9d70523SRafael J. Wysocki static char err_suspend[] __initdata = 68a9d70523SRafael J. Wysocki KERN_ERR "PM: suspend test failed, error %d\n"; 69a9d70523SRafael J. Wysocki static char info_test[] __initdata = 70a9d70523SRafael J. Wysocki KERN_INFO "PM: test RTC wakeup from '%s' suspend\n"; 71a9d70523SRafael J. Wysocki 72a9d70523SRafael J. Wysocki unsigned long now; 73a9d70523SRafael J. Wysocki struct rtc_wkalrm alm; 74a9d70523SRafael J. Wysocki int status; 75a9d70523SRafael J. Wysocki 76a9d70523SRafael J. Wysocki /* this may fail if the RTC hasn't been initialized */ 77a9d70523SRafael J. Wysocki status = rtc_read_time(rtc, &alm.time); 78a9d70523SRafael J. Wysocki if (status < 0) { 79a9d70523SRafael J. Wysocki printk(err_readtime, dev_name(&rtc->dev), status); 80a9d70523SRafael J. Wysocki return; 81a9d70523SRafael J. Wysocki } 82a9d70523SRafael J. Wysocki rtc_tm_to_time(&alm.time, &now); 83a9d70523SRafael J. Wysocki 84a9d70523SRafael J. Wysocki memset(&alm, 0, sizeof alm); 85a9d70523SRafael J. Wysocki rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time); 86a9d70523SRafael J. Wysocki alm.enabled = true; 87a9d70523SRafael J. Wysocki 88a9d70523SRafael J. Wysocki status = rtc_set_alarm(rtc, &alm); 89a9d70523SRafael J. Wysocki if (status < 0) { 90a9d70523SRafael J. Wysocki printk(err_wakealarm, dev_name(&rtc->dev), status); 91a9d70523SRafael J. Wysocki return; 92a9d70523SRafael J. Wysocki } 93a9d70523SRafael J. Wysocki 94a9d70523SRafael J. Wysocki if (state == PM_SUSPEND_MEM) { 95*d431cbc5SRafael J. Wysocki printk(info_test, pm_states[state]); 96a9d70523SRafael J. Wysocki status = pm_suspend(state); 97a9d70523SRafael J. Wysocki if (status == -ENODEV) 98a9d70523SRafael J. Wysocki state = PM_SUSPEND_STANDBY; 99a9d70523SRafael J. Wysocki } 100a9d70523SRafael J. Wysocki if (state == PM_SUSPEND_STANDBY) { 101*d431cbc5SRafael J. Wysocki printk(info_test, pm_states[state]); 102a9d70523SRafael J. Wysocki status = pm_suspend(state); 103a9d70523SRafael J. Wysocki } 104a9d70523SRafael J. Wysocki if (status < 0) 105a9d70523SRafael J. Wysocki printk(err_suspend, status); 106a9d70523SRafael J. Wysocki 107a9d70523SRafael J. Wysocki /* Some platforms can't detect that the alarm triggered the 108a9d70523SRafael J. Wysocki * wakeup, or (accordingly) disable it after it afterwards. 109a9d70523SRafael J. Wysocki * It's supposed to give oneshot behavior; cope. 110a9d70523SRafael J. Wysocki */ 111a9d70523SRafael J. Wysocki alm.enabled = false; 112a9d70523SRafael J. Wysocki rtc_set_alarm(rtc, &alm); 113a9d70523SRafael J. Wysocki } 114a9d70523SRafael J. Wysocki 1159f3b795aSMichał Mirosław static int __init has_wakealarm(struct device *dev, const void *data) 116a9d70523SRafael J. Wysocki { 117a9d70523SRafael J. Wysocki struct rtc_device *candidate = to_rtc_device(dev); 118a9d70523SRafael J. Wysocki 119a9d70523SRafael J. Wysocki if (!candidate->ops->set_alarm) 120a9d70523SRafael J. Wysocki return 0; 121a9d70523SRafael J. Wysocki if (!device_may_wakeup(candidate->dev.parent)) 122a9d70523SRafael J. Wysocki return 0; 123a9d70523SRafael J. Wysocki 124a9d70523SRafael J. Wysocki return 1; 125a9d70523SRafael J. Wysocki } 126a9d70523SRafael J. Wysocki 127a9d70523SRafael J. Wysocki /* 128a9d70523SRafael J. Wysocki * Kernel options like "test_suspend=mem" force suspend/resume sanity tests 129a9d70523SRafael J. Wysocki * at startup time. They're normally disabled, for faster boot and because 130a9d70523SRafael J. Wysocki * we can't know which states really work on this particular system. 131a9d70523SRafael J. Wysocki */ 132a9d70523SRafael J. Wysocki static suspend_state_t test_state __initdata = PM_SUSPEND_ON; 133a9d70523SRafael J. Wysocki 134a9d70523SRafael J. Wysocki static char warn_bad_state[] __initdata = 135a9d70523SRafael J. Wysocki KERN_WARNING "PM: can't test '%s' suspend state\n"; 136a9d70523SRafael J. Wysocki 137a9d70523SRafael J. Wysocki static int __init setup_test_suspend(char *value) 138a9d70523SRafael J. Wysocki { 13927ddcc65SRafael J. Wysocki suspend_state_t i; 140a9d70523SRafael J. Wysocki 141a9d70523SRafael J. Wysocki /* "=mem" ==> "mem" */ 142a9d70523SRafael J. Wysocki value++; 14327ddcc65SRafael J. Wysocki for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) 144*d431cbc5SRafael J. Wysocki if (!strcmp(pm_states[i], value)) { 145*d431cbc5SRafael J. Wysocki test_state = i; 146a9d70523SRafael J. Wysocki return 0; 147a9d70523SRafael J. Wysocki } 14827ddcc65SRafael J. Wysocki 149a9d70523SRafael J. Wysocki printk(warn_bad_state, value); 150a9d70523SRafael J. Wysocki return 0; 151a9d70523SRafael J. Wysocki } 152a9d70523SRafael J. Wysocki __setup("test_suspend", setup_test_suspend); 153a9d70523SRafael J. Wysocki 154a9d70523SRafael J. Wysocki static int __init test_suspend(void) 155a9d70523SRafael J. Wysocki { 156a9d70523SRafael J. Wysocki static char warn_no_rtc[] __initdata = 157a9d70523SRafael J. Wysocki KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n"; 158a9d70523SRafael J. Wysocki 159a9d70523SRafael J. Wysocki struct rtc_device *rtc = NULL; 1609f3b795aSMichał Mirosław struct device *dev; 161a9d70523SRafael J. Wysocki 162a9d70523SRafael J. Wysocki /* PM is initialized by now; is that state testable? */ 163a9d70523SRafael J. Wysocki if (test_state == PM_SUSPEND_ON) 164a9d70523SRafael J. Wysocki goto done; 165*d431cbc5SRafael J. Wysocki if (!pm_states[test_state]) { 166*d431cbc5SRafael J. Wysocki printk(warn_bad_state, pm_states[test_state]); 167a9d70523SRafael J. Wysocki goto done; 168a9d70523SRafael J. Wysocki } 169a9d70523SRafael J. Wysocki 170a9d70523SRafael J. Wysocki /* RTCs have initialized by now too ... can we use one? */ 1719f3b795aSMichał Mirosław dev = class_find_device(rtc_class, NULL, NULL, has_wakealarm); 1729f3b795aSMichał Mirosław if (dev) 1739f3b795aSMichał Mirosław rtc = rtc_class_open(dev_name(dev)); 174a9d70523SRafael J. Wysocki if (!rtc) { 175a9d70523SRafael J. Wysocki printk(warn_no_rtc); 176a9d70523SRafael J. Wysocki goto done; 177a9d70523SRafael J. Wysocki } 178a9d70523SRafael J. Wysocki 179a9d70523SRafael J. Wysocki /* go for it */ 180a9d70523SRafael J. Wysocki test_wakealarm(rtc, test_state); 181a9d70523SRafael J. Wysocki rtc_class_close(rtc); 182a9d70523SRafael J. Wysocki done: 183a9d70523SRafael J. Wysocki return 0; 184a9d70523SRafael J. Wysocki } 185a9d70523SRafael J. Wysocki late_initcall(test_suspend); 186