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authorShuoX Liu <shuox.liu@intel.com>2011-08-10 23:01:26 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2011-10-16 23:27:45 +0200
commit2a77c46de1e3dace73745015635ebbc648eca69c (patch)
treea801ed6ba5623c7d963377906776ade6f02eea0a /kernel
parent9bd717c0dc8224cadfd66df7eeff98c987711d98 (diff)
PM / Suspend: Add statistics debugfs file for suspend to RAM
Record S3 failure time about each reason and the latest two failed devices' names in S3 progress. We can check it through 'suspend_stats' entry in debugfs. The motivation of the patch: We are enabling power features on Medfield. Comparing with PC/notebook, a mobile enters/exits suspend-2-ram (we call it s3 on Medfield) far more frequently. If it can't enter suspend-2-ram in time, the power might be used up soon. We often find sometimes, a device suspend fails. Then, system retries s3 over and over again. As display is off, testers and developers don't know what happens. Some testers and developers complain they don't know if system tries suspend-2-ram, and what device fails to suspend. They need such info for a quick check. The patch adds suspend_stats under debugfs for users to check suspend to RAM statistics quickly. If not using this patch, we have other methods to get info about what device fails. One is to turn on CONFIG_PM_DEBUG, but users would get too much info and testers need recompile the system. In addition, dynamic debug is another good tool to dump debug info. But it still doesn't match our utilization scenario closely. 1) user need write a user space parser to process the syslog output; 2) Our testing scenario is we leave the mobile for at least hours. Then, check its status. No serial console available during the testing. One is because console would be suspended, and the other is serial console connecting with spi or HSU devices would consume power. These devices are powered off at suspend-2-ram. Signed-off-by: ShuoX Liu <shuox.liu@intel.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/power/main.c102
-rw-r--r--kernel/power/suspend.c17
2 files changed, 116 insertions, 3 deletions
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 6c601f87196..2757acba8e8 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 b6b71ad2208..595a3dd56a8 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);