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PM: Separate suspend to RAM functionality from core

Browse Source 
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>
This commit is contained in:
Rafael J. Wysocki 2009-06-10 01:27:12 +02:00
parent 783ea7d4ee
commit a9d7052363
5 changed files with 505 additions and 504 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
kernel/power/Makefile
View File

@ -6,6 +6,8 @@ endif
obj-$(CONFIG_PM) += main.o
obj-$(CONFIG_PM_SLEEP) += console.o
obj-$(CONFIG_FREEZER) += process.o
obj-$(CONFIG_SUSPEND) += suspend.o
obj-$(CONFIG_PM_TEST_SUSPEND) += suspend_test.o
obj-$(CONFIG_HIBERNATION) += swsusp.o disk.o snapshot.o swap.o user.o
obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o

503
kernel/power/main.c
View File

@ -8,20 +8,9 @@
*
*/
#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/kobject.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/resume-trace.h>
#include <linux/freezer.h>
#include <linux/vmstat.h>
#include <linux/syscalls.h>
#include "power.h"
@ -119,355 +108,6 @@ power_attr(pm_test);
#endif /* CONFIG_PM_SLEEP */
#ifdef CONFIG_SUSPEND
static int suspend_test(int level)
{
#ifdef CONFIG_PM_DEBUG
if (pm_test_level == level) {
printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
mdelay(5000);
return 1;
}
#endif /* !CONFIG_PM_DEBUG */
return 0;
}
#ifdef CONFIG_PM_TEST_SUSPEND
/*
* 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.
*/
#define TEST_SUSPEND_SECONDS 5
static unsigned long suspend_test_start_time;
static 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;
}
static 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\n", label);
}
#else
static void suspend_test_start(void)
{
}
static void suspend_test_finish(const char *label)
{
}
#endif
static struct platform_suspend_ops *suspend_ops;
/**
* suspend_set_ops - Set the global suspend method table.
* @ops: Pointer to ops structure.
*/
void suspend_set_ops(struct platform_suspend_ops *ops)
{
mutex_lock(&pm_mutex);
suspend_ops = ops;
mutex_unlock(&pm_mutex);
}
/**
* suspend_valid_only_mem - generic memory-only valid callback
*
* Platform drivers that implement mem suspend only and only need
* to check for that in their .valid callback can use this instead
* of rolling their own .valid callback.
*/
int suspend_valid_only_mem(suspend_state_t state)
{
return state == PM_SUSPEND_MEM;
}
/**
* suspend_prepare - Do prep work before entering low-power state.
*
* This is common code that is called for each state that we're entering.
* Run suspend notifiers, allocate a console and stop all processes.
*/
static int suspend_prepare(void)
{
int error;
if (!suspend_ops || !suspend_ops->enter)
return -EPERM;
pm_prepare_console();
error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
if (error)
goto Finish;
error = usermodehelper_disable();
if (error)
goto Finish;
error = suspend_freeze_processes();
if (!error)
return 0;
suspend_thaw_processes();
usermodehelper_enable();
Finish:
pm_notifier_call_chain(PM_POST_SUSPEND);
pm_restore_console();
return error;
}
/* default implementation */
void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
{
local_irq_disable();
}
/* default implementation */
void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
{
local_irq_enable();
}
/**
* suspend_enter - enter the desired system sleep state.
* @state: state to enter
*
* This function should be called after devices have been suspended.
*/
static int suspend_enter(suspend_state_t state)
{
int error;
if (suspend_ops->prepare) {
error = suspend_ops->prepare();
if (error)
return error;
}
error = dpm_suspend_noirq(PMSG_SUSPEND);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down\n");
goto Platfrom_finish;
}
if (suspend_ops->prepare_late) {
error = suspend_ops->prepare_late();
if (error)
goto Power_up_devices;
}
if (suspend_test(TEST_PLATFORM))
goto Platform_wake;
error = disable_nonboot_cpus();
if (error || suspend_test(TEST_CPUS))
goto Enable_cpus;
arch_suspend_disable_irqs();
BUG_ON(!irqs_disabled());
error = sysdev_suspend(PMSG_SUSPEND);
if (!error) {
if (!suspend_test(TEST_CORE))
error = suspend_ops->enter(state);
sysdev_resume();
}
arch_suspend_enable_irqs();
BUG_ON(irqs_disabled());
Enable_cpus:
enable_nonboot_cpus();
Platform_wake:
if (suspend_ops->wake)
suspend_ops->wake();
Power_up_devices:
dpm_resume_noirq(PMSG_RESUME);
Platfrom_finish:
if (suspend_ops->finish)
suspend_ops->finish();
return error;
}
/**
* suspend_devices_and_enter - suspend devices and enter the desired system
* sleep state.
* @state: state to enter
*/
int suspend_devices_and_enter(suspend_state_t state)
{
int error;
if (!suspend_ops)
return -ENOSYS;
if (suspend_ops->begin) {
error = suspend_ops->begin(state);
if (error)
goto Close;
}
suspend_console();
suspend_test_start();
error = dpm_suspend_start(PMSG_SUSPEND);
if (error) {
printk(KERN_ERR "PM: Some devices failed to suspend\n");
goto Recover_platform;
}
suspend_test_finish("suspend devices");
if (suspend_test(TEST_DEVICES))
goto Recover_platform;
suspend_enter(state);
Resume_devices:
suspend_test_start();
dpm_resume_end(PMSG_RESUME);
suspend_test_finish("resume devices");
resume_console();
Close:
if (suspend_ops->end)
suspend_ops->end();
return error;
Recover_platform:
if (suspend_ops->recover)
suspend_ops->recover();
goto Resume_devices;
}
/**
* suspend_finish - Do final work before exiting suspend sequence.
*
* Call platform code to clean up, restart processes, and free the
* console that we've allocated. This is not called for suspend-to-disk.
*/
static void suspend_finish(void)
{
suspend_thaw_processes();
usermodehelper_enable();
pm_notifier_call_chain(PM_POST_SUSPEND);
pm_restore_console();
}
static const char * const pm_states[PM_SUSPEND_MAX] = {
[PM_SUSPEND_STANDBY] = "standby",
[PM_SUSPEND_MEM] = "mem",
};
static inline int valid_state(suspend_state_t state)
{
/* All states need lowlevel support and need to be valid
* to the lowlevel implementation, no valid callback
* implies that none are valid. */
if (!suspend_ops || !suspend_ops->valid || !suspend_ops->valid(state))
return 0;
return 1;
}
/**
* enter_state - Do common work of entering low-power state.
* @state: pm_state structure for state we're entering.
*
* Make sure we're the only ones trying to enter a sleep state. Fail
* if someone has beat us to it, since we don't want anything weird to
* happen when we wake up.
* Then, do the setup for suspend, enter the state, and cleaup (after
* we've woken up).
*/
static int enter_state(suspend_state_t state)
{
int error;
if (!valid_state(state))
return -ENODEV;
if (!mutex_trylock(&pm_mutex))
return -EBUSY;
printk(KERN_INFO "PM: Syncing filesystems ... ");
sys_sync();
printk("done.\n");
pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
error = suspend_prepare();
if (error)
goto Unlock;
if (suspend_test(TEST_FREEZER))
goto Finish;
pr_debug("PM: Entering %s sleep\n", pm_states[state]);
error = suspend_devices_and_enter(state);
Finish:
pr_debug("PM: Finishing wakeup.\n");
suspend_finish();
Unlock:
mutex_unlock(&pm_mutex);
return error;
}
/**
* pm_suspend - Externally visible function for suspending system.
* @state: Enumerated value of state to enter.
*
* Determine whether or not value is within range, get state
* structure, and enter (above).
*/
int pm_suspend(suspend_state_t state)
{
if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
return enter_state(state);
return -EINVAL;
}
EXPORT_SYMBOL(pm_suspend);
#endif /* CONFIG_SUSPEND */
struct kobject *power_kobj;
/**
@ -480,7 +120,6 @@ struct kobject *power_kobj;
* store() accepts one of those strings, translates it into the
* proper enumerated value, and initiates a suspend transition.
*/
static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
@ -578,7 +217,6 @@ static struct attribute_group attr_group = {
.attrs = g,
};
static int __init pm_init(void)
{
power_kobj = kobject_create_and_add("power", NULL);
@ -588,144 +226,3 @@ static int __init pm_init(void)
}
core_initcall(pm_init);
#ifdef CONFIG_PM_TEST_SUSPEND
#include <linux/rtc.h>
/*
* 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 */
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)
printk(err_suspend, status);
/* 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);
}
static int __init has_wakealarm(struct device *dev, void *name_ptr)
{
struct rtc_device *candidate = to_rtc_device(dev);
if (!candidate->ops->set_alarm)
return 0;
if (!device_may_wakeup(candidate->dev.parent))
return 0;
*(const char **)name_ptr = dev_name(dev);
return 1;
}
/*
* 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 suspend_state_t test_state __initdata = PM_SUSPEND_ON;
static char warn_bad_state[] __initdata =
KERN_WARNING "PM: can't test '%s' suspend state\n";
static int __init setup_test_suspend(char *value)
{
unsigned i;
/* "=mem" ==> "mem" */
value++;
for (i = 0; i < PM_SUSPEND_MAX; i++) {
if (!pm_states[i])
continue;
if (strcmp(pm_states[i], value) != 0)
continue;
test_state = (__force suspend_state_t) i;
return 0;
}
printk(warn_bad_state, value);
return 0;
}
__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";
char *pony = NULL;
struct rtc_device *rtc = NULL;
/* PM is initialized by now; is that state testable? */
if (test_state == PM_SUSPEND_ON)
goto done;
if (!valid_state(test_state)) {
printk(warn_bad_state, pm_states[test_state]);
goto done;
}
/* RTCs have initialized by now too ... can we use one? */
class_find_device(rtc_class, NULL, &pony, has_wakealarm);
if (pony)
rtc = rtc_class_open(pony);
if (!rtc) {
printk(warn_no_rtc);
goto done;
}
/* go for it */
test_wakealarm(rtc, test_state);
rtc_class_close(rtc);
done:
return 0;
}
late_initcall(test_suspend);
#endif /* CONFIG_PM_TEST_SUSPEND */

17
kernel/power/power.h
View File

@ -160,15 +160,30 @@ extern void swsusp_show_speed(struct timeval *, struct timeval *,
unsigned int, char *);
#ifdef CONFIG_SUSPEND
/* kernel/power/main.c */
/* kernel/power/suspend.c */
extern const char *const pm_states[];
extern bool valid_state(suspend_state_t state);
extern int suspend_devices_and_enter(suspend_state_t state);
extern int enter_state(suspend_state_t state);
#else /* !CONFIG_SUSPEND */
static inline int suspend_devices_and_enter(suspend_state_t state)
{
return -ENOSYS;
}
static inline int enter_state(suspend_state_t state) { return -ENOSYS; }
static inline bool valid_state(suspend_state_t state) { return false; }
#endif /* !CONFIG_SUSPEND */
#ifdef CONFIG_PM_TEST_SUSPEND
/* kernel/power/suspend_test.c */
extern void suspend_test_start(void);
extern void suspend_test_finish(const char *label);
#else /* !CONFIG_PM_TEST_SUSPEND */
static inline void suspend_test_start(void) {}
static inline void suspend_test_finish(const char *label) {}
#endif /* !CONFIG_PM_TEST_SUSPEND */
#ifdef CONFIG_PM_SLEEP
/* kernel/power/main.c */
extern int pm_notifier_call_chain(unsigned long val);

300
kernel/power/suspend.c Normal file
View File

@ -0,0 +1,300 @@
/*
* kernel/power/suspend.c - Suspend to RAM and standby functionality.
*
* Copyright (c) 2003 Patrick Mochel
* Copyright (c) 2003 Open Source Development Lab
* Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
*
* This file is released under the GPLv2.
*/
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/syscalls.h>
#include "power.h"
const char *const pm_states[PM_SUSPEND_MAX] = {
[PM_SUSPEND_STANDBY] = "standby",
[PM_SUSPEND_MEM] = "mem",
};
static struct platform_suspend_ops *suspend_ops;
/**
* suspend_set_ops - Set the global suspend method table.
* @ops: Pointer to ops structure.
*/
void suspend_set_ops(struct platform_suspend_ops *ops)
{
mutex_lock(&pm_mutex);
suspend_ops = ops;
mutex_unlock(&pm_mutex);
}
bool valid_state(suspend_state_t state)
{
/*
* All states need lowlevel support and need to be valid to the lowlevel
* implementation, no valid callback implies that none are valid.
*/
return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
}
/**
* suspend_valid_only_mem - generic memory-only valid callback
*
* Platform drivers that implement mem suspend only and only need
* to check for that in their .valid callback can use this instead
* of rolling their own .valid callback.
*/
int suspend_valid_only_mem(suspend_state_t state)
{
return state == PM_SUSPEND_MEM;
}
static int suspend_test(int level)
{
#ifdef CONFIG_PM_DEBUG
if (pm_test_level == level) {
printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
mdelay(5000);
return 1;
}
#endif /* !CONFIG_PM_DEBUG */
return 0;
}
/**
* suspend_prepare - Do prep work before entering low-power state.
*
* This is common code that is called for each state that we're entering.
* Run suspend notifiers, allocate a console and stop all processes.
*/
static int suspend_prepare(void)
{
int error;
if (!suspend_ops || !suspend_ops->enter)
return -EPERM;
pm_prepare_console();
error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
if (error)
goto Finish;
error = usermodehelper_disable();
if (error)
goto Finish;
error = suspend_freeze_processes();
if (!error)
return 0;
suspend_thaw_processes();
usermodehelper_enable();
Finish:
pm_notifier_call_chain(PM_POST_SUSPEND);
pm_restore_console();
return error;
}
/* default implementation */
void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
{
local_irq_disable();
}
/* default implementation */
void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
{
local_irq_enable();
}
/**
* suspend_enter - enter the desired system sleep state.
* @state: state to enter
*
* This function should be called after devices have been suspended.
*/
static int suspend_enter(suspend_state_t state)
{
int error;
if (suspend_ops->prepare) {
error = suspend_ops->prepare();
if (error)
return error;
}
error = dpm_suspend_noirq(PMSG_SUSPEND);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down\n");
goto Platfrom_finish;
}
if (suspend_ops->prepare_late) {
error = suspend_ops->prepare_late();
if (error)
goto Power_up_devices;
}
if (suspend_test(TEST_PLATFORM))
goto Platform_wake;
error = disable_nonboot_cpus();
if (error || suspend_test(TEST_CPUS))
goto Enable_cpus;
arch_suspend_disable_irqs();
BUG_ON(!irqs_disabled());
error = sysdev_suspend(PMSG_SUSPEND);
if (!error) {
if (!suspend_test(TEST_CORE))
error = suspend_ops->enter(state);
sysdev_resume();
}
arch_suspend_enable_irqs();
BUG_ON(irqs_disabled());
Enable_cpus:
enable_nonboot_cpus();
Platform_wake:
if (suspend_ops->wake)
suspend_ops->wake();
Power_up_devices:
dpm_resume_noirq(PMSG_RESUME);
Platfrom_finish:
if (suspend_ops->finish)
suspend_ops->finish();
return error;
}
/**
* suspend_devices_and_enter - suspend devices and enter the desired system
* sleep state.
* @state: state to enter
*/
int suspend_devices_and_enter(suspend_state_t state)
{
int error;
if (!suspend_ops)
return -ENOSYS;
if (suspend_ops->begin) {
error = suspend_ops->begin(state);
if (error)
goto Close;
}
suspend_console();
suspend_test_start();
error = dpm_suspend_start(PMSG_SUSPEND);
if (error) {
printk(KERN_ERR "PM: Some devices failed to suspend\n");
goto Recover_platform;
}
suspend_test_finish("suspend devices");
if (suspend_test(TEST_DEVICES))
goto Recover_platform;
suspend_enter(state);
Resume_devices:
suspend_test_start();
dpm_resume_end(PMSG_RESUME);
suspend_test_finish("resume devices");
resume_console();
Close:
if (suspend_ops->end)
suspend_ops->end();
return error;
Recover_platform:
if (suspend_ops->recover)
suspend_ops->recover();
goto Resume_devices;
}
/**
* suspend_finish - Do final work before exiting suspend sequence.
*
* Call platform code to clean up, restart processes, and free the
* console that we've allocated. This is not called for suspend-to-disk.
*/
static void suspend_finish(void)
{
suspend_thaw_processes();
usermodehelper_enable();
pm_notifier_call_chain(PM_POST_SUSPEND);
pm_restore_console();
}
/**
* enter_state - Do common work of entering low-power state.
* @state: pm_state structure for state we're entering.
*
* Make sure we're the only ones trying to enter a sleep state. Fail
* if someone has beat us to it, since we don't want anything weird to
* happen when we wake up.
* Then, do the setup for suspend, enter the state, and cleaup (after
* we've woken up).
*/
int enter_state(suspend_state_t state)
{
int error;
if (!valid_state(state))
return -ENODEV;
if (!mutex_trylock(&pm_mutex))
return -EBUSY;
printk(KERN_INFO "PM: Syncing filesystems ... ");
sys_sync();
printk("done.\n");
pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
error = suspend_prepare();
if (error)
goto Unlock;
if (suspend_test(TEST_FREEZER))
goto Finish;
pr_debug("PM: Entering %s sleep\n", pm_states[state]);
error = suspend_devices_and_enter(state);
Finish:
pr_debug("PM: Finishing wakeup.\n");
suspend_finish();
Unlock:
mutex_unlock(&pm_mutex);
return error;
}
/**
* pm_suspend - Externally visible function for suspending system.
* @state: Enumerated value of state to enter.
*
* Determine whether or not value is within range, get state
* structure, and enter (above).
*/
int pm_suspend(suspend_state_t state)
{
if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
return enter_state(state);
return -EINVAL;
}
EXPORT_SYMBOL(pm_suspend);

187
kernel/power/suspend_test.c Normal file
View File

@ -0,0 +1,187 @@
/*
* kernel/power/suspend_test.c - Suspend to RAM and standby test facility.
*
* Copyright (c) 2009 Pavel Machek <pavel@ucw.cz>
*
* 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.
*/
#define TEST_SUSPEND_SECONDS 5
static unsigned long suspend_test_start_time;
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;
}
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\n", label);
}
/*
* 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 */
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)
printk(err_suspend, status);
/* 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);
}
static int __init has_wakealarm(struct device *dev, void *name_ptr)
{
struct rtc_device *candidate = to_rtc_device(dev);
if (!candidate->ops->set_alarm)
return 0;
if (!device_may_wakeup(candidate->dev.parent))
return 0;
*(const char **)name_ptr = dev_name(dev);
return 1;
}
/*
* 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 suspend_state_t test_state __initdata = PM_SUSPEND_ON;
static char warn_bad_state[] __initdata =
KERN_WARNING "PM: can't test '%s' suspend state\n";
static int __init setup_test_suspend(char *value)
{
unsigned i;
/* "=mem" ==> "mem" */
value++;
for (i = 0; i < PM_SUSPEND_MAX; i++) {
if (!pm_states[i])
continue;
if (strcmp(pm_states[i], value) != 0)
continue;
test_state = (__force suspend_state_t) i;
return 0;
}
printk(warn_bad_state, value);
return 0;
}
__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";
char *pony = NULL;
struct rtc_device *rtc = NULL;
/* PM is initialized by now; is that state testable? */
if (test_state == PM_SUSPEND_ON)
goto done;
if (!valid_state(test_state)) {
printk(warn_bad_state, pm_states[test_state]);
goto done;
}
/* RTCs have initialized by now too ... can we use one? */
class_find_device(rtc_class, NULL, &pony, has_wakealarm);
if (pony)
rtc = rtc_class_open(pony);
if (!rtc) {
printk(warn_no_rtc);
goto done;
}
/* go for it */
test_wakealarm(rtc, test_state);
rtc_class_close(rtc);
done:
return 0;
}
late_initcall(test_suspend);