2 files changed, 116 insertions, 3 deletions

diff --git a/kernel/power/main.c b/kernel/power/main.c
index 6c601f871964..2757acba8e8a 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 b6b71ad2208f..595a3dd56a8a 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);