From 0e7d56e3d9d7e37c79d0e05ffb3994e34beb3bbc Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 19 Nov 2007 23:41:19 +0100 Subject: [PATCH] Suspend: Testing facility (rev. 2) MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Introduce sysfs attribute /sys/power/pm_test allowing one to test the suspend core code.  Namely, writing one of the strings: freezer devices platform processors core to this file causes the suspend code to work in one of the test modes defined as follows: freezer - test the freezing of processes devices - test the freezing of processes and suspending of devices platform - test the freezing of processes, suspending of devices and platform global   control methods(*) processors - test the freezing of processes, suspending of devices, platform global   control methods and the disabling of nonboot CPUs core - test the freezing of processes, suspending of devices, platform global   control methods, the disabling of nonboot CPUs and suspending of   platform/system devices (*) These are ACPI global control methods on ACPI systems Then, if a suspend is started by normal means, the suspend core will perform its normal operations up to the point indicated by given test level.  Next, it will wait for 5 seconds and carry out the resume operations needed to transition the system back to the fully functional state. Writing "none" to /sys/power/pm_test turns the testing off. When open for reading, /sys/power/pm_test contains a space-separated list of all available tests (including "none" that represents the normal functionality) in which the current test level is indicated by square brackets. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Len Brown --- kernel/power/main.c | 108 +++++++++++++++++++++++++++++++++++++++---- kernel/power/power.h | 18 ++++++++ 2 files changed, 117 insertions(+), 9 deletions(-) diff --git a/kernel/power/main.c b/kernel/power/main.c index efc08360e6..84e1ae63bb 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -31,6 +31,79 @@ DEFINE_MUTEX(pm_mutex); unsigned int pm_flags; EXPORT_SYMBOL(pm_flags); +#ifdef CONFIG_PM_DEBUG +int pm_test_level = TEST_NONE; + +static int suspend_test(int level) +{ + if (pm_test_level == level) { + printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n"); + mdelay(5000); + return 1; + } + return 0; +} + +static const char * const pm_tests[__TEST_AFTER_LAST] = { + [TEST_NONE] = "none", + [TEST_CORE] = "core", + [TEST_CPUS] = "processors", + [TEST_PLATFORM] = "platform", + [TEST_DEVICES] = "devices", + [TEST_FREEZER] = "freezer", +}; + +static ssize_t pm_test_show(struct kset *kset, char *buf) +{ + char *s = buf; + int level; + + for (level = TEST_FIRST; level <= TEST_MAX; level++) + if (pm_tests[level]) { + if (level == pm_test_level) + s += sprintf(s, "[%s] ", pm_tests[level]); + else + s += sprintf(s, "%s ", pm_tests[level]); + } + + if (s != buf) + /* convert the last space to a newline */ + *(s-1) = '\n'; + + return (s - buf); +} + +static ssize_t pm_test_store(struct kset *kset, const char *buf, size_t n) +{ + const char * const *s; + int level; + char *p; + int len; + int error = -EINVAL; + + p = memchr(buf, '\n', n); + len = p ? p - buf : n; + + mutex_lock(&pm_mutex); + + level = TEST_FIRST; + for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++) + if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) { + pm_test_level = level; + error = 0; + break; + } + + mutex_unlock(&pm_mutex); + + return error ? error : n; +} + +power_attr(pm_test); +#else /* !CONFIG_PM_DEBUG */ +static inline int suspend_test(int level) { return 0; } +#endif /* !CONFIG_PM_DEBUG */ + #ifdef CONFIG_SUSPEND /* This is just an arbitrary number */ @@ -136,7 +209,10 @@ static int suspend_enter(suspend_state_t state) printk(KERN_ERR "Some devices failed to power down\n"); goto Done; } - error = suspend_ops->enter(state); + + if (!suspend_test(TEST_CORE)) + error = suspend_ops->enter(state); + device_power_up(); Done: arch_suspend_enable_irqs(); @@ -167,16 +243,25 @@ int suspend_devices_and_enter(suspend_state_t state) printk(KERN_ERR "Some devices failed to suspend\n"); goto Resume_console; } + + if (suspend_test(TEST_DEVICES)) + goto Resume_devices; + if (suspend_ops->prepare) { error = suspend_ops->prepare(); if (error) goto Resume_devices; } + + if (suspend_test(TEST_PLATFORM)) + goto Finish; + error = disable_nonboot_cpus(); - if (!error) + if (!error && !suspend_test(TEST_CPUS)) suspend_enter(state); enable_nonboot_cpus(); + Finish: if (suspend_ops->finish) suspend_ops->finish(); Resume_devices: @@ -243,12 +328,17 @@ static int enter_state(suspend_state_t state) printk("done.\n"); pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); - if ((error = suspend_prepare())) + 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: @@ -369,18 +459,18 @@ pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr, } power_attr(pm_trace); +#endif /* CONFIG_PM_TRACE */ static struct attribute * g[] = { &state_attr.attr, +#ifdef CONFIG_PM_TRACE &pm_trace_attr.attr, +#endif +#ifdef CONFIG_PM_DEBUG + &pm_test_attr.attr, +#endif NULL, }; -#else -static struct attribute * g[] = { - &state_attr.attr, - NULL, -}; -#endif /* CONFIG_PM_TRACE */ static struct attribute_group attr_group = { .attrs = g, diff --git a/kernel/power/power.h b/kernel/power/power.h index c5321eb1f7..9f9e16e339 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -188,3 +188,21 @@ int restore_highmem(void); static inline unsigned int count_highmem_pages(void) { return 0; } static inline int restore_highmem(void) { return 0; } #endif + +/* + * Suspend test levels + */ +enum { + /* keep first */ + TEST_NONE, + TEST_CORE, + TEST_CPUS, + TEST_PLATFORM, + TEST_DEVICES, + TEST_FREEZER, + /* keep last */ + __TEST_AFTER_LAST +}; + +#define TEST_FIRST TEST_NONE +#define TEST_MAX (__TEST_AFTER_LAST - 1) -- 2.39.5