diff --git a/Documentation/power/basic-pm-debugging.txt b/Documentation/power/basic-pm-debugging.txt
index ddd78172ef738d2c3f52dcea70f61cb0591670c2..62eca080a71b2313196b4588dfa817dae5ed573a 100644
--- a/Documentation/power/basic-pm-debugging.txt
+++ b/Documentation/power/basic-pm-debugging.txt
@@ -201,3 +201,27 @@ case, you may be able to search for failing drivers by following the procedure
analogous to the one described in section 1. If you find some failing drivers,
you will have to unload them every time before an STR transition (ie. before
you run s2ram), and please report the problems with them.
+
+There is a debugfs entry which shows the suspend to RAM statistics. Here is an
+example of its output.
+ # mount -t debugfs none /sys/kernel/debug
+ # cat /sys/kernel/debug/suspend_stats
+ success: 20
+ fail: 5
+ failed_freeze: 0
+ failed_prepare: 0
+ failed_suspend: 5
+ failed_suspend_noirq: 0
+ failed_resume: 0
+ failed_resume_noirq: 0
+ failures:
+ last_failed_dev: alarm
+ adc
+ last_failed_errno: -16
+ -16
+ last_failed_step: suspend
+ suspend
+Field success means the success number of suspend to RAM, and field fail means
+the failure number. Others are the failure number of different steps of suspend
+to RAM. suspend_stats just lists the last 2 failed devices, error number and
+failed step of suspend.
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index c6291ab725a32c04baa74e4f5e0ff7f29bc2969a..b1b58260b4ffbb7c3bcff7451bcfd1c61a1135d7 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -46,6 +46,7 @@ LIST_HEAD(dpm_prepared_list);
LIST_HEAD(dpm_suspended_list);
LIST_HEAD(dpm_noirq_list);
+struct suspend_stats suspend_stats;
static DEFINE_MUTEX(dpm_list_mtx);
static pm_message_t pm_transition;
@@ -467,8 +468,12 @@ void dpm_resume_noirq(pm_message_t state)
mutex_unlock(&dpm_list_mtx);
error = device_resume_noirq(dev, state);
- if (error)
+ if (error) {
+ suspend_stats.failed_resume_noirq++;
+ dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
+ dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, " early", error);
+ }
mutex_lock(&dpm_list_mtx);
put_device(dev);
@@ -629,8 +634,12 @@ void dpm_resume(pm_message_t state)
mutex_unlock(&dpm_list_mtx);
error = device_resume(dev, state, false);
- if (error)
+ if (error) {
+ suspend_stats.failed_resume++;
+ dpm_save_failed_step(SUSPEND_RESUME);
+ dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, "", error);
+ }
mutex_lock(&dpm_list_mtx);
}
@@ -805,6 +814,9 @@ int dpm_suspend_noirq(pm_message_t state)
mutex_lock(&dpm_list_mtx);
if (error) {
pm_dev_err(dev, state, " late", error);
+ suspend_stats.failed_suspend_noirq++;
+ dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
+ dpm_save_failed_dev(dev_name(dev));
put_device(dev);
break;
}
@@ -926,8 +938,10 @@ static void async_suspend(void *data, async_cookie_t cookie)
int error;
error = __device_suspend(dev, pm_transition, true);
- if (error)
+ if (error) {
+ dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, pm_transition, " async", error);
+ }
put_device(dev);
}
@@ -970,6 +984,7 @@ int dpm_suspend(pm_message_t state)
mutex_lock(&dpm_list_mtx);
if (error) {
pm_dev_err(dev, state, "", error);
+ dpm_save_failed_dev(dev_name(dev));
put_device(dev);
break;
}
@@ -983,7 +998,10 @@ int dpm_suspend(pm_message_t state)
async_synchronize_full();
if (!error)
error = async_error;
- if (!error)
+ if (error) {
+ suspend_stats.failed_suspend++;
+ dpm_save_failed_step(SUSPEND_SUSPEND);
+ } else
dpm_show_time(starttime, state, NULL);
return error;
}
@@ -1091,7 +1109,10 @@ int dpm_suspend_start(pm_message_t state)
int error;
error = dpm_prepare(state);
- if (!error)
+ if (error) {
+ suspend_stats.failed_prepare++;
+ dpm_save_failed_step(SUSPEND_PREPARE);
+ } else
error = dpm_suspend(state);
return error;
}
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 6bbcef22e1054766f01a36f6e352c0ea5d06770c..76f42e49b72deea43a190677822070bea4e53eb1 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -34,6 +34,58 @@ typedef int __bitwise suspend_state_t;
#define PM_SUSPEND_MEM ((__force suspend_state_t) 3)
#define PM_SUSPEND_MAX ((__force suspend_state_t) 4)
+enum suspend_stat_step {
+ SUSPEND_FREEZE = 1,
+ SUSPEND_PREPARE,
+ SUSPEND_SUSPEND,
+ SUSPEND_SUSPEND_NOIRQ,
+ SUSPEND_RESUME_NOIRQ,
+ SUSPEND_RESUME
+};
+
+struct suspend_stats {
+ int success;
+ int fail;
+ int failed_freeze;
+ int failed_prepare;
+ int failed_suspend;
+ int failed_suspend_noirq;
+ int failed_resume;
+ int failed_resume_noirq;
+#define REC_FAILED_NUM 2
+ int last_failed_dev;
+ char failed_devs[REC_FAILED_NUM][40];
+ int last_failed_errno;
+ int errno[REC_FAILED_NUM];
+ int last_failed_step;
+ enum suspend_stat_step failed_steps[REC_FAILED_NUM];
+};
+
+extern struct suspend_stats suspend_stats;
+
+static inline void dpm_save_failed_dev(const char *name)
+{
+ strlcpy(suspend_stats.failed_devs[suspend_stats.last_failed_dev],
+ name,
+ sizeof(suspend_stats.failed_devs[0]));
+ suspend_stats.last_failed_dev++;
+ suspend_stats.last_failed_dev %= REC_FAILED_NUM;
+}
+
+static inline void dpm_save_failed_errno(int err)
+{
+ suspend_stats.errno[suspend_stats.last_failed_errno] = err;
+ suspend_stats.last_failed_errno++;
+ suspend_stats.last_failed_errno %= REC_FAILED_NUM;
+}
+
+static inline void dpm_save_failed_step(enum suspend_stat_step step)
+{
+ suspend_stats.failed_steps[suspend_stats.last_failed_step] = step;
+ suspend_stats.last_failed_step++;
+ suspend_stats.last_failed_step %= REC_FAILED_NUM;
+}
+
/**
* struct platform_suspend_ops - Callbacks for managing platform dependent
* system sleep states.
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 6c601f871964408e7df2b376dd69d86006103b0e..2757acba8e8a08459517c6d77b895df84044bf80 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -12,6 +12,8 @@
#include <linux/string.h>
#include <linux/resume-trace.h>
#include <linux/workqueue.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
#include "power.h"
@@ -133,6 +135,101 @@ power_attr(pm_test);
#endif /* CONFIG_PM_SLEEP */
+#ifdef CONFIG_DEBUG_FS
+static char *suspend_step_name(enum suspend_stat_step step)
+{
+ switch (step) {
+ case SUSPEND_FREEZE:
+ return "freeze";
+ case SUSPEND_PREPARE:
+ return "prepare";
+ case SUSPEND_SUSPEND:
+ return "suspend";
+ case SUSPEND_SUSPEND_NOIRQ:
+ return "suspend_noirq";
+ case SUSPEND_RESUME_NOIRQ:
+ return "resume_noirq";
+ case SUSPEND_RESUME:
+ return "resume";
+ default:
+ return "";
+ }
+}
+
+static int suspend_stats_show(struct seq_file *s, void *unused)
+{
+ int i, index, last_dev, last_errno, last_step;
+
+ last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
+ last_dev %= REC_FAILED_NUM;
+ last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
+ last_errno %= REC_FAILED_NUM;
+ last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
+ last_step %= REC_FAILED_NUM;
+ seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
+ "%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
+ "success", suspend_stats.success,
+ "fail", suspend_stats.fail,
+ "failed_freeze", suspend_stats.failed_freeze,
+ "failed_prepare", suspend_stats.failed_prepare,
+ "failed_suspend", suspend_stats.failed_suspend,
+ "failed_suspend_noirq",
+ suspend_stats.failed_suspend_noirq,
+ "failed_resume", suspend_stats.failed_resume,
+ "failed_resume_noirq",
+ suspend_stats.failed_resume_noirq);
+ seq_printf(s, "failures:\n last_failed_dev:\t%-s\n",
+ suspend_stats.failed_devs[last_dev]);
+ for (i = 1; i < REC_FAILED_NUM; i++) {
+ index = last_dev + REC_FAILED_NUM - i;
+ index %= REC_FAILED_NUM;
+ seq_printf(s, "\t\t\t%-s\n",
+ suspend_stats.failed_devs[index]);
+ }
+ seq_printf(s, " last_failed_errno:\t%-d\n",
+ suspend_stats.errno[last_errno]);
+ for (i = 1; i < REC_FAILED_NUM; i++) {
+ index = last_errno + REC_FAILED_NUM - i;
+ index %= REC_FAILED_NUM;
+ seq_printf(s, "\t\t\t%-d\n",
+ suspend_stats.errno[index]);
+ }
+ seq_printf(s, " last_failed_step:\t%-s\n",
+ suspend_step_name(
+ suspend_stats.failed_steps[last_step]));
+ for (i = 1; i < REC_FAILED_NUM; i++) {
+ index = last_step + REC_FAILED_NUM - i;
+ index %= REC_FAILED_NUM;
+ seq_printf(s, "\t\t\t%-s\n",
+ suspend_step_name(
+ suspend_stats.failed_steps[index]));
+ }
+
+ return 0;
+}
+
+static int suspend_stats_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, suspend_stats_show, NULL);
+}
+
+static const struct file_operations suspend_stats_operations = {
+ .open = suspend_stats_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init pm_debugfs_init(void)
+{
+ debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
+ NULL, NULL, &suspend_stats_operations);
+ return 0;
+}
+
+late_initcall(pm_debugfs_init);
+#endif /* CONFIG_DEBUG_FS */
+
struct kobject *power_kobj;
/**
@@ -194,6 +291,11 @@ static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
}
if (state < PM_SUSPEND_MAX && *s)
error = enter_state(state);
+ if (error) {
+ suspend_stats.fail++;
+ dpm_save_failed_errno(error);
+ } else
+ suspend_stats.success++;
#endif
Exit:
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index b6b71ad2208fd1a0a04bd31fe4437f6d99bf7f9d..595a3dd56a8a832c9029086de9b2a11460951d3d 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -104,7 +104,10 @@ static int suspend_prepare(void)
goto Finish;
error = suspend_freeze_processes();
- if (!error)
+ if (error) {
+ suspend_stats.failed_freeze++;
+ dpm_save_failed_step(SUSPEND_FREEZE);
+ } else
return 0;
suspend_thaw_processes();
@@ -315,8 +318,16 @@ int enter_state(suspend_state_t state)
*/
int pm_suspend(suspend_state_t state)
{
- if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
- return enter_state(state);
+ int ret;
+ if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) {
+ ret = enter_state(state);
+ if (ret) {
+ suspend_stats.fail++;
+ dpm_save_failed_errno(ret);
+ } else
+ suspend_stats.success++;
+ return ret;
+ }
return -EINVAL;
}
EXPORT_SYMBOL(pm_suspend);