From: Zhang Jiejing <jiejing.zhang@xxxxxxxxxxxxx>
This patch add function to check each device's suspend time
consumption. If any driver takes more time that the threshold (default
0.5 ms), it will print a warnning message including the device and bus
name on the console. You can change the threshold on-the-fly by
modify file '/sys/power/device_suspend_time_threshold' to adjust this
value,the unit is in microsecond.
The output is like:
PM: device (bus) :(device name) suspend/resume too slow, takes (time) msencs.
PM: device platform:soc-audio.2 suspend too slow, takes 606.696 msecs
PM: device platform:mxc_sdc_fb.1 suspend too slow, takes 7.708 msecs
Signed-off-by: Zhang Jiejing <jiejing.zhang@xxxxxxxxxxxxx>
---
drivers/base/power/main.c | 40 +++++++++++++++++++++++++++++++++++++++-
drivers/base/power/power.h | 3 +++
kernel/power/Kconfig | 15 +++++++++++++++
kernel/power/main.c | 32 ++++++++++++++++++++++++++++++++
4 files changed, 89 insertions(+), 1 deletions(-)
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 052dc53..000243c 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -178,6 +178,40 @@ static void initcall_debug_report(struct device *dev, ktime_t calltime,
}
}
+#ifdef CONFIG_SUSPEND_DEVICE_TIME_DEBUG
+static void suspend_time_debug_start(ktime_t *start)
+{
+ *start = ktime_get();
+}
+
+static void suspend_time_debug_report(const char *name, struct device *dev,
+ ktime_t starttime)
+{
+ ktime_t rettime;
+ s64 usecs64;
+ int usecs;
+
+ if (!dev->driver)
+ return;
+
+ rettime = ktime_get();
+ usecs64 = ktime_to_us(ktime_sub(rettime, starttime));
+ usecs = usecs64;
+ if (usecs == 0)
+ usecs = 1;
+
+ if (device_suspend_time_threshold
+ && usecs > device_suspend_time_threshold)
+ pr_info("PM: device %s:%s %s too slow, it takes \t %ld.%03ld mses\n",
+ dev->bus->name, dev_name(dev), name,
+ usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
+}
+#else
+static void suspend_time_debug_start(ktime_t *start) {}
+static void suspend_time_debug_report(const char *name, struct device *dev,
+ ktime_t starttime) {}
+#endif /* CONFIG_SUSPEND_DEVICE_TIME_DEBUG */
+
/**
* dpm_wait - Wait for a PM operation to complete.
* @dev: Device to wait for.
@@ -214,7 +248,7 @@ static int pm_op(struct device *dev,
pm_message_t state)
{
int error = 0;
- ktime_t calltime;
+ ktime_t calltime, starttime;
calltime = initcall_debug_start(dev);
@@ -222,13 +256,17 @@ static int pm_op(struct device *dev,
#ifdef CONFIG_SUSPEND
case PM_EVENT_SUSPEND:
if (ops->suspend) {
+ suspend_time_debug_start(&starttime);
error = ops->suspend(dev);
+ suspend_time_debug_report("suspend", dev, starttime);
suspend_report_result(ops->suspend, error);
}
break;
case PM_EVENT_RESUME:
if (ops->resume) {
+ suspend_time_debug_start(&starttime);
error = ops->resume(dev);
+ suspend_time_debug_report("resume", dev, starttime);
suspend_report_result(ops->resume, error);
}
break;
diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h
index f2a25f1..72d5963 100644
--- a/drivers/base/power/power.h
+++ b/drivers/base/power/power.h
@@ -18,6 +18,9 @@ extern int pm_async_enabled;
/* drivers/base/power/main.c */
extern struct list_head dpm_list; /* The active device list */
+/* driver/base/power/main.c */
+extern int device_suspend_time_threshold;
+
static inline struct device *to_device(struct list_head *entry)
{
return container_of(entry, struct device, power.entry);
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 4603f08..9b82c4b 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -87,6 +87,21 @@ config PM_SLEEP
def_bool y
depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE
+config SUSPEND_DEVICE_TIME_DEBUG
+ bool "Warnning device suspend/resume takes too much time"
+ depends on SUSPEND && PM_DEBUG
+ default n
+ ---help---
+
+ This option will enable a timing function to check each device
+ suspend time consumption, If the device takes more time that
+ the threshold (default 0.5 ms), it will print the device and
+ bus name on the console. You can change the threshold
+ on-the-fly by modify "/sys/power/device_suspend_time_threshold"
+ the unit is in microsecond.
+
+ This options only for debug proprose, If in doubt, say N.
+
config PM_SLEEP_SMP
def_bool y
depends on SMP
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 8eaba5f..d2e734f 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -297,12 +297,44 @@ power_attr(pm_trace_dev_match);
#endif /* CONFIG_PM_TRACE */
+#ifdef CONFIG_SUSPEND_DEVICE_TIME_DEBUG
+/*
+ * threshold of device suspend time consumption in microsecond(0.5ms), the
+ * driver suspend/resume time longer than this threshold will be
+ * print to console, 0 to disable */
+int device_suspend_time_threshold = 500;
+
+static ssize_t
+device_suspend_time_threshold_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", device_suspend_time_threshold);
+}
+
+static ssize_t
+device_suspend_time_threshold_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t n)
+{
+ int val;
+ if (sscanf(buf, "%d", &val) > 0) {
+ device_suspend_time_threshold = val;
+ return n;
+ }
+ return -EINVAL;
+}
+power_attr(device_suspend_time_threshold);
+#endif
+
static struct attribute * g[] = {
&state_attr.attr,
#ifdef CONFIG_PM_TRACE
&pm_trace_attr.attr,
&pm_trace_dev_match_attr.attr,
#endif
+#ifdef CONFIG_SUSPEND_DEVICE_TIME_DEBUG
+ &device_suspend_time_threshold_attr.attr,
+#endif
#ifdef CONFIG_PM_SLEEP
&pm_async_attr.attr,
&wakeup_count_attr.attr,
--
1.7.1
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