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![Rafael J. Wysocki](/assets/img/avatar_default.png)
Move the suspend to RAM and standby code from kernel/power/main.c to two separate files, kernel/power/suspend.c containing the basic functions and kernel/power/suspend_test.c containing the automatic suspend test facility based on the RTC clock alarm. There are no changes in functionality related to these modifications. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz>
187 lines
4.9 KiB
C
187 lines
4.9 KiB
C
/*
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* kernel/power/suspend_test.c - Suspend to RAM and standby test facility.
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*
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* Copyright (c) 2009 Pavel Machek <pavel@ucw.cz>
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*
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* This file is released under the GPLv2.
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*/
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#include <linux/init.h>
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#include <linux/rtc.h>
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#include "power.h"
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/*
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* We test the system suspend code by setting an RTC wakealarm a short
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* time in the future, then suspending. Suspending the devices won't
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* normally take long ... some systems only need a few milliseconds.
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*
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* The time it takes is system-specific though, so when we test this
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* during system bootup we allow a LOT of time.
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*/
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#define TEST_SUSPEND_SECONDS 5
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static unsigned long suspend_test_start_time;
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void suspend_test_start(void)
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{
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/* FIXME Use better timebase than "jiffies", ideally a clocksource.
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* What we want is a hardware counter that will work correctly even
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* during the irqs-are-off stages of the suspend/resume cycle...
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*/
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suspend_test_start_time = jiffies;
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}
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void suspend_test_finish(const char *label)
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{
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long nj = jiffies - suspend_test_start_time;
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unsigned msec;
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msec = jiffies_to_msecs(abs(nj));
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pr_info("PM: %s took %d.%03d seconds\n", label,
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msec / 1000, msec % 1000);
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/* Warning on suspend means the RTC alarm period needs to be
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* larger -- the system was sooo slooowwww to suspend that the
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* alarm (should have) fired before the system went to sleep!
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*
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* Warning on either suspend or resume also means the system
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* has some performance issues. The stack dump of a WARN_ON
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* is more likely to get the right attention than a printk...
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*/
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WARN(msec > (TEST_SUSPEND_SECONDS * 1000), "Component: %s\n", label);
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}
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/*
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* To test system suspend, we need a hands-off mechanism to resume the
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* system. RTCs wake alarms are a common self-contained mechanism.
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*/
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static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state)
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{
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static char err_readtime[] __initdata =
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KERN_ERR "PM: can't read %s time, err %d\n";
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static char err_wakealarm [] __initdata =
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KERN_ERR "PM: can't set %s wakealarm, err %d\n";
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static char err_suspend[] __initdata =
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KERN_ERR "PM: suspend test failed, error %d\n";
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static char info_test[] __initdata =
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KERN_INFO "PM: test RTC wakeup from '%s' suspend\n";
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unsigned long now;
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struct rtc_wkalrm alm;
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int status;
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/* this may fail if the RTC hasn't been initialized */
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status = rtc_read_time(rtc, &alm.time);
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if (status < 0) {
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printk(err_readtime, dev_name(&rtc->dev), status);
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return;
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}
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rtc_tm_to_time(&alm.time, &now);
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memset(&alm, 0, sizeof alm);
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rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time);
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alm.enabled = true;
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status = rtc_set_alarm(rtc, &alm);
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if (status < 0) {
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printk(err_wakealarm, dev_name(&rtc->dev), status);
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return;
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}
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if (state == PM_SUSPEND_MEM) {
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printk(info_test, pm_states[state]);
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status = pm_suspend(state);
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if (status == -ENODEV)
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state = PM_SUSPEND_STANDBY;
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}
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if (state == PM_SUSPEND_STANDBY) {
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printk(info_test, pm_states[state]);
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status = pm_suspend(state);
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}
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if (status < 0)
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printk(err_suspend, status);
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/* Some platforms can't detect that the alarm triggered the
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* wakeup, or (accordingly) disable it after it afterwards.
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* It's supposed to give oneshot behavior; cope.
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*/
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alm.enabled = false;
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rtc_set_alarm(rtc, &alm);
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}
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static int __init has_wakealarm(struct device *dev, void *name_ptr)
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{
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struct rtc_device *candidate = to_rtc_device(dev);
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if (!candidate->ops->set_alarm)
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return 0;
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if (!device_may_wakeup(candidate->dev.parent))
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return 0;
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*(const char **)name_ptr = dev_name(dev);
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return 1;
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}
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/*
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* Kernel options like "test_suspend=mem" force suspend/resume sanity tests
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* at startup time. They're normally disabled, for faster boot and because
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* we can't know which states really work on this particular system.
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*/
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static suspend_state_t test_state __initdata = PM_SUSPEND_ON;
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static char warn_bad_state[] __initdata =
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KERN_WARNING "PM: can't test '%s' suspend state\n";
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static int __init setup_test_suspend(char *value)
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{
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unsigned i;
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/* "=mem" ==> "mem" */
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value++;
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for (i = 0; i < PM_SUSPEND_MAX; i++) {
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if (!pm_states[i])
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continue;
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if (strcmp(pm_states[i], value) != 0)
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continue;
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test_state = (__force suspend_state_t) i;
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return 0;
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}
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printk(warn_bad_state, value);
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return 0;
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}
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__setup("test_suspend", setup_test_suspend);
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static int __init test_suspend(void)
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{
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static char warn_no_rtc[] __initdata =
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KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n";
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char *pony = NULL;
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struct rtc_device *rtc = NULL;
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/* PM is initialized by now; is that state testable? */
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if (test_state == PM_SUSPEND_ON)
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goto done;
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if (!valid_state(test_state)) {
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printk(warn_bad_state, pm_states[test_state]);
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goto done;
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}
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/* RTCs have initialized by now too ... can we use one? */
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class_find_device(rtc_class, NULL, &pony, has_wakealarm);
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if (pony)
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rtc = rtc_class_open(pony);
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if (!rtc) {
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printk(warn_no_rtc);
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goto done;
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}
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/* go for it */
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test_wakealarm(rtc, test_state);
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rtc_class_close(rtc);
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done:
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return 0;
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}
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late_initcall(test_suspend);
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