[PATCH v4 1/4] include/linux/suspend.h: Only show pm_pr_dbg messages at suspend/resume

[xiongxin]

From: Mario Limonciello <mario.limonciello@xxxxxxx>

All uses in the kernel are currently already oriented around
suspend/resume. As some other parts of the kernel may also use these
messages in functions that could also be used outside of
suspend/resume, only enable in suspend/resume path.

Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
v3->v4:
 * add back do/while as it wasn't pointless.  It fixes a warning.
---
 include/linux/suspend.h | 8 +++++---
 kernel/power/main.c     | 6 ++++++
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 1a0426e6761c..74f406c53ac0 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -555,6 +555,7 @@ static inline void unlock_system_sleep(unsigned int flags) {}
 #ifdef CONFIG_PM_SLEEP_DEBUG
 extern bool pm_print_times_enabled;
 extern bool pm_debug_messages_on;
+extern bool pm_debug_messages_should_print(void);
 static inline int pm_dyn_debug_messages_on(void)
 {
 #ifdef CONFIG_DYNAMIC_DEBUG
@@ -568,14 +569,14 @@ static inline int pm_dyn_debug_messages_on(void)
 #endif
 #define __pm_pr_dbg(fmt, ...)					\
 	do {							\
-		if (pm_debug_messages_on)			\
+		if (pm_debug_messages_should_print())		\
 			printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__);	\
 		else if (pm_dyn_debug_messages_on())		\
 			pr_debug(fmt, ##__VA_ARGS__);	\
 	} while (0)
 #define __pm_deferred_pr_dbg(fmt, ...)				\
 	do {							\
-		if (pm_debug_messages_on)			\
+		if (pm_debug_messages_should_print())		\
 			printk_deferred(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__);	\
 	} while (0)
 #else
@@ -593,7 +594,8 @@ static inline int pm_dyn_debug_messages_on(void)
 /**
  * pm_pr_dbg - print pm sleep debug messages
  *
- * If pm_debug_messages_on is enabled, print message.
+ * If pm_debug_messages_on is enabled and the system is entering/leaving
+ *      suspend, print message.
  * If pm_debug_messages_on is disabled and CONFIG_DYNAMIC_DEBUG is enabled,
  *	print message only from instances explicitly enabled on dynamic debug's
  *	control.
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 3113ec2f1db4..daa535012e51 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -556,6 +556,12 @@ power_attr_ro(pm_wakeup_irq);
 
 bool pm_debug_messages_on __read_mostly;
 
+bool pm_debug_messages_should_print(void)
+{
+	return pm_debug_messages_on && pm_suspend_target_state != PM_SUSPEND_ON;

> hibernate processes also mostly use the pm_pr_dbg() function, which
> results in hibernate processes only being able to output such logs
> through dynamic debug, which is unfriendly to kernels without
> CONFIG_DYNAMIC_DEBUG configuration.

+}
+EXPORT_SYMBOL_GPL(pm_debug_messages_should_print);
+
 static ssize_t pm_debug_messages_show(struct kobject *kobj,
 				      struct kobj_attribute *attr, char *buf)
 {

-- 
2.34.1