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Release 4.15 kernel/power/suspend_test.c

Directory: kernel/power
 * kernel/power/suspend_test.c - Suspend to RAM and standby test facility.
 * Copyright (c) 2009 Pavel Machek <>
 * This file is released under the GPLv2.

#include <linux/init.h>
#include <linux/rtc.h>

#include "power.h"

 * We test the system suspend code by setting an RTC wakealarm a short
 * time in the future, then suspending.  Suspending the devices won't
 * normally take long ... some systems only need a few milliseconds.
 * The time it takes is system-specific though, so when we test this
 * during system bootup we allow a LOT of time.


static unsigned long suspend_test_start_time;

static u32 test_repeat_count_max = 1;

static u32 test_repeat_count_current;

void suspend_test_start(void) { /* FIXME Use better timebase than "jiffies", ideally a clocksource. * What we want is a hardware counter that will work correctly even * during the irqs-are-off stages of the suspend/resume cycle... */ suspend_test_start_time = jiffies; }


Rafael J. Wysocki12100.00%1100.00%

void suspend_test_finish(const char *label) { long nj = jiffies - suspend_test_start_time; unsigned msec; msec = jiffies_to_msecs(abs(nj)); pr_info("PM: %s took %d.%03d seconds\n", label, msec / 1000, msec % 1000); /* Warning on suspend means the RTC alarm period needs to be * larger -- the system was sooo slooowwww to suspend that the * alarm (should have) fired before the system went to sleep! * * Warning on either suspend or resume also means the system * has some performance issues. The stack dump of a WARN_ON * is more likely to get the right attention than a printk... */ WARN(msec > (TEST_SUSPEND_SECONDS * 1000), "Component: %s, time: %u\n", label, msec); }


Rafael J. Wysocki63100.00%2100.00%

/* * To test system suspend, we need a hands-off mechanism to resume the * system. RTCs wake alarms are a common self-contained mechanism. */
static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state) { static char err_readtime[] __initdata = KERN_ERR "PM: can't read %s time, err %d\n"; static char err_wakealarm [] __initdata = KERN_ERR "PM: can't set %s wakealarm, err %d\n"; static char err_suspend[] __initdata = KERN_ERR "PM: suspend test failed, error %d\n"; static char info_test[] __initdata = KERN_INFO "PM: test RTC wakeup from '%s' suspend\n"; unsigned long now; struct rtc_wkalrm alm; int status; /* this may fail if the RTC hasn't been initialized */ repeat: status = rtc_read_time(rtc, &alm.time); if (status < 0) { printk(err_readtime, dev_name(&rtc->dev), status); return; } rtc_tm_to_time(&alm.time, &now); memset(&alm, 0, sizeof alm); rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time); alm.enabled = true; status = rtc_set_alarm(rtc, &alm); if (status < 0) { printk(err_wakealarm, dev_name(&rtc->dev), status); return; } if (state == PM_SUSPEND_MEM) { printk(info_test, pm_states[state]); status = pm_suspend(state); if (status == -ENODEV) state = PM_SUSPEND_STANDBY; } if (state == PM_SUSPEND_STANDBY) { printk(info_test, pm_states[state]); status = pm_suspend(state); if (status < 0) state = PM_SUSPEND_TO_IDLE; } if (state == PM_SUSPEND_TO_IDLE) { printk(info_test, pm_states[state]); status = pm_suspend(state); } if (status < 0) printk(err_suspend, status); test_repeat_count_current++; if (test_repeat_count_current < test_repeat_count_max) goto repeat; /* Some platforms can't detect that the alarm triggered the * wakeup, or (accordingly) disable it after it afterwards. * It's supposed to give oneshot behavior; cope. */ alm.enabled = false; rtc_set_alarm(rtc, &alm); }


Rafael J. Wysocki26484.89%250.00%
Srinivas Pandruvada4715.11%250.00%

static int __init has_wakealarm(struct device *dev, const void *data) { struct rtc_device *candidate = to_rtc_device(dev); if (!candidate->ops->set_alarm) return 0; if (!device_may_wakeup(candidate->dev.parent)) return 0; return 1; }


Rafael J. Wysocki5596.49%150.00%
Michał Mirosław23.51%150.00%

/* * Kernel options like "test_suspend=mem" force suspend/resume sanity tests * at startup time. They're normally disabled, for faster boot and because * we can't know which states really work on this particular system. */ static const char *test_state_label __initdata; static char warn_bad_state[] __initdata = KERN_WARNING "PM: can't test '%s' suspend state\n";
static int __init setup_test_suspend(char *value) { int i; char *repeat; char *suspend_type; /* example : "=mem[,N]" ==> "mem[,N]" */ value++; suspend_type = strsep(&value, ","); if (!suspend_type) return 0; repeat = strsep(&value, ","); if (repeat) { if (kstrtou32(repeat, 0, &test_repeat_count_max)) return 0; } for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) if (!strcmp(pm_labels[i], suspend_type)) { test_state_label = pm_labels[i]; return 0; } printk(warn_bad_state, suspend_type); return 0; }


Rafael J. Wysocki6048.78%360.00%
Srinivas Pandruvada6048.78%120.00%
Geert Uytterhoeven32.44%120.00%

__setup("test_suspend", setup_test_suspend);
static int __init test_suspend(void) { static char warn_no_rtc[] __initdata = KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n"; struct rtc_device *rtc = NULL; struct device *dev; suspend_state_t test_state; /* PM is initialized by now; is that state testable? */ if (!test_state_label) return 0; for (test_state = PM_SUSPEND_MIN; test_state < PM_SUSPEND_MAX; test_state++) { const char *state_label = pm_states[test_state]; if (state_label && !strcmp(test_state_label, state_label)) break; } if (test_state == PM_SUSPEND_MAX) { printk(warn_bad_state, test_state_label); return 0; } /* RTCs have initialized by now too ... can we use one? */ dev = class_find_device(rtc_class, NULL, NULL, has_wakealarm); if (dev) { rtc = rtc_class_open(dev_name(dev)); put_device(dev); } if (!rtc) { printk(warn_no_rtc); return 0; } /* go for it */ test_wakealarm(rtc, test_state); rtc_class_close(rtc); return 0; }


Rafael J. Wysocki14487.80%360.00%
Michał Mirosław137.93%120.00%
Johan Hovold74.27%120.00%


Overall Contributors

Rafael J. Wysocki64882.03%654.55%
Srinivas Pandruvada11714.81%218.18%
Michał Mirosław151.90%19.09%
Johan Hovold70.89%19.09%
Geert Uytterhoeven30.38%19.09%
Directory: kernel/power
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