PM / sleep: add pm-trace support for suspending phase

Occasionally, the system can't come back up after suspend/resume
due to problems of device suspending phase. This patch make
PM_TRACE infrastructure cover device suspending phase of
suspend/resume process, and the information in RTC can tell
developers which device suspending function make system hang.

Signed-off-by: Zhonghui Fu <zhonghui.fu@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

arch/x86/include/asm/resume-trace.h → arch/x86/include/asm/pm-trace.h

@@ -1,5 +1,5 @@
-#ifndef _ASM_X86_RESUME_TRACE_H
-#define _ASM_X86_RESUME_TRACE_H
+#ifndef _ASM_X86_PM_TRACE_H
+#define _ASM_X86_PM_TRACE_H
 
 #include <asm/asm.h>
 
@@ -14,8 +14,10 @@ do {								\
 			     ".previous"			\
 			     :"=r" (tracedata)			\
 			     : "i" (__LINE__), "i" (__FILE__));	\
-		generate_resume_trace(tracedata, user);		\
+		generate_pm_trace(tracedata, user);		\
 	}							\
 } while (0)
 
-#endif /* _ASM_X86_RESUME_TRACE_H */
+#define TRACE_SUSPEND(user)	TRACE_RESUME(user)
+
+#endif /* _ASM_X86_PM_TRACE_H */

drivers/base/power/main.c

@@ -23,7 +23,7 @@
 #include <linux/mutex.h>
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
-#include <linux/resume-trace.h>
+#include <linux/pm-trace.h>
 #include <linux/interrupt.h>
 #include <linux/sched.h>
 #include <linux/async.h>
@@ -1017,6 +1017,9 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a
 	char *info = NULL;
 	int error = 0;
 
+	TRACE_DEVICE(dev);
+	TRACE_SUSPEND(0);
+
 	if (async_error)
 		goto Complete;
 
@@ -1057,6 +1060,7 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a
 
 Complete:
 	complete_all(&dev->power.completion);
+	TRACE_SUSPEND(error);
 	return error;
 }
 
@@ -1078,7 +1082,7 @@ static int device_suspend_noirq(struct device *dev)
 {
 	reinit_completion(&dev->power.completion);
 
-	if (pm_async_enabled && dev->power.async_suspend) {
+	if (is_async(dev)) {
 		get_device(dev);
 		async_schedule(async_suspend_noirq, dev);
 		return 0;
@@ -1157,6 +1161,9 @@ static int __device_suspend_late(struct device *dev, pm_message_t state, bool as
 	char *info = NULL;
 	int error = 0;
 
+	TRACE_DEVICE(dev);
+	TRACE_SUSPEND(0);
+
 	__pm_runtime_disable(dev, false);
 
 	if (async_error)
@@ -1198,6 +1205,7 @@ static int __device_suspend_late(struct device *dev, pm_message_t state, bool as
 		async_error = error;
 
 Complete:
+	TRACE_SUSPEND(error);
 	complete_all(&dev->power.completion);
 	return error;
 }
@@ -1219,7 +1227,7 @@ static int device_suspend_late(struct device *dev)
 {
 	reinit_completion(&dev->power.completion);
 
-	if (pm_async_enabled && dev->power.async_suspend) {
+	if (is_async(dev)) {
 		get_device(dev);
 		async_schedule(async_suspend_late, dev);
 		return 0;
@@ -1338,6 +1346,9 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 	int error = 0;
 	DECLARE_DPM_WATCHDOG_ON_STACK(wd);
 
+	TRACE_DEVICE(dev);
+	TRACE_SUSPEND(0);
+
 	dpm_wait_for_children(dev, async);
 
 	if (async_error)
@@ -1444,6 +1455,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 	if (error)
 		async_error = error;
 
+	TRACE_SUSPEND(error);
 	return error;
 }
 
@@ -1465,7 +1477,7 @@ static int device_suspend(struct device *dev)
 {
 	reinit_completion(&dev->power.completion);
 
-	if (pm_async_enabled && dev->power.async_suspend) {
+	if (is_async(dev)) {
 		get_device(dev);
 		async_schedule(async_suspend, dev);
 		return 0;

drivers/base/power/trace.c

@@ -7,7 +7,7 @@
  * devices may be working.
  */
 
-#include <linux/resume-trace.h>
+#include <linux/pm-trace.h>
 #include <linux/export.h>
 #include <linux/rtc.h>
 
@@ -154,7 +154,7 @@ EXPORT_SYMBOL(set_trace_device);
  * it's not any guarantee, but it's a high _likelihood_ that
  * the match is valid).
  */
-void generate_resume_trace(const void *tracedata, unsigned int user)
+void generate_pm_trace(const void *tracedata, unsigned int user)
 {
 	unsigned short lineno = *(unsigned short *)tracedata;
 	const char *file = *(const char **)(tracedata + 2);
@@ -164,7 +164,7 @@ void generate_resume_trace(const void *tracedata, unsigned int user)
 	file_hash_value = hash_string(lineno, file, FILEHASH);
 	set_magic_time(user_hash_value, file_hash_value, dev_hash_value);
 }
-EXPORT_SYMBOL(generate_resume_trace);
+EXPORT_SYMBOL(generate_pm_trace);
 
 extern char __tracedata_start, __tracedata_end;
 static int show_file_hash(unsigned int value)

include/linux/resume-trace.h → include/linux/pm-trace.h

@@ -1,8 +1,8 @@
-#ifndef RESUME_TRACE_H
-#define RESUME_TRACE_H
+#ifndef PM_TRACE_H
+#define PM_TRACE_H
 
 #ifdef CONFIG_PM_TRACE
-#include <asm/resume-trace.h>
+#include <asm/pm-trace.h>
 #include <linux/types.h>
 
 extern int pm_trace_enabled;
@@ -14,7 +14,7 @@ static inline int pm_trace_is_enabled(void)
 
 struct device;
 extern void set_trace_device(struct device *);
-extern void generate_resume_trace(const void *tracedata, unsigned int user);
+extern void generate_pm_trace(const void *tracedata, unsigned int user);
 extern int show_trace_dev_match(char *buf, size_t size);
 
 #define TRACE_DEVICE(dev) do { \
@@ -28,6 +28,7 @@ static inline int pm_trace_is_enabled(void) { return 0; }
 
 #define TRACE_DEVICE(dev) do { } while (0)
 #define TRACE_RESUME(dev) do { } while (0)
+#define TRACE_SUSPEND(dev) do { } while (0)
 
 #endif
 

kernel/power/main.c

@@ -11,7 +11,7 @@
 #include <linux/export.h>
 #include <linux/kobject.h>
 #include <linux/string.h>
-#include <linux/resume-trace.h>
+#include <linux/pm-trace.h>
 #include <linux/workqueue.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>