@@ -201,3 +201,22 @@ 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
+ failed_devs:
+ last_failed: alarm
+ adc
+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.
@@ -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;
@@ -180,6 +181,15 @@ static void initcall_debug_report(struct device *dev, ktime_t calltime,
}
}
+static void dpm_save_dev_name(const char *name)
+{
+ strlcpy(suspend_stats.failed_devs[suspend_stats.last_failed],
+ name,
+ sizeof(suspend_stats.failed_devs[0]));
+ suspend_stats.last_failed++;
+ suspend_stats.last_failed %= REC_FAILED_DEV_NUM;
+}
+
/**
* dpm_wait - Wait for a PM operation to complete.
* @dev: Device to wait for.
@@ -464,8 +474,11 @@ 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_dev_name(dev_name(dev));
pm_dev_err(dev, state, " early", error);
+ }
mutex_lock(&dpm_list_mtx);
put_device(dev);
@@ -626,8 +639,11 @@ 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_dev_name(dev_name(dev));
pm_dev_err(dev, state, "", error);
+ }
mutex_lock(&dpm_list_mtx);
}
@@ -802,6 +818,8 @@ 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_dev_name(dev_name(dev));
put_device(dev);
break;
}
@@ -923,8 +941,10 @@ 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_dev_name(dev_name(dev));
pm_dev_err(dev, pm_transition, " async", error);
+ }
put_device(dev);
}
@@ -967,6 +987,7 @@ int dpm_suspend(pm_message_t state)
mutex_lock(&dpm_list_mtx);
if (error) {
pm_dev_err(dev, state, "", error);
+ dpm_save_dev_name(dev_name(dev));
put_device(dev);
break;
}
@@ -982,6 +1003,8 @@ int dpm_suspend(pm_message_t state)
error = async_error;
if (!error)
dpm_show_time(starttime, state, NULL);
+ else
+ suspend_stats.failed_suspend++;
return error;
}
@@ -1090,6 +1113,8 @@ int dpm_suspend_start(pm_message_t state)
error = dpm_prepare(state);
if (!error)
error = dpm_suspend(state);
+ else
+ suspend_stats.failed_prepare++;
return error;
}
EXPORT_SYMBOL_GPL(dpm_suspend_start);
@@ -34,6 +34,22 @@ typedef int __bitwise suspend_state_t;
#define PM_SUSPEND_MEM ((__force suspend_state_t) 3)
#define PM_SUSPEND_MAX ((__force suspend_state_t) 4)
+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_DEV_NUM 2
+ char failed_devs[REC_FAILED_DEV_NUM][40];
+ int last_failed;
+};
+
+extern struct suspend_stats suspend_stats;
+
/**
* struct platform_suspend_ops - Callbacks for managing platform dependent
* system sleep states.
@@ -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 +135,59 @@ power_attr(pm_test);
#endif /* CONFIG_PM_SLEEP */
+#ifdef CONFIG_DEBUG_FS
+static int suspend_stats_show(struct seq_file *s, void *unused)
+{
+ int i, index, last_index;
+
+ last_index = suspend_stats.last_failed + REC_FAILED_DEV_NUM - 1;
+ last_index %= REC_FAILED_DEV_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, "failed_devs:\n last_failed:\t%s\n",
+ suspend_stats.failed_devs[last_index]);
+ for (i = 1; i < REC_FAILED_DEV_NUM; i++) {
+ index = last_index + REC_FAILED_DEV_NUM - i;
+ index %= REC_FAILED_DEV_NUM;
+ seq_printf(s, "\t\t%s\n",
+ suspend_stats.failed_devs[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 +249,10 @@ 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++;
+ else
+ suspend_stats.success++;
#endif
Exit:
@@ -106,6 +106,8 @@ static int suspend_prepare(void)
error = suspend_freeze_processes();
if (!error)
return 0;
+ else
+ suspend_stats.failed_freeze++;
suspend_thaw_processes();
usermodehelper_enable();
@@ -315,8 +317,15 @@ 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++;
+ else
+ suspend_stats.success++;
+ return ret;
+ }
return -EINVAL;
}
EXPORT_SYMBOL(pm_suspend);