[PATCH v2] power: Include additional information in pm_print_times

[Shuah Khan]

Change __device_suspend() path to include driver name and the ops that
get run for a device. This additional information helps associate the
driver and the type of pm_ops the device uses in the suspend path very
quickly which will aid in debugging problems in suspend and resume paths.
Changed both start and end debug messages to include pm_ops information
and use dev_info() instead of pr_info().

dmesg output before the change:

[  164.390032] calling  1-1+ @ 69, parent: usb1
[  164.390035] call 1-1+ returned 0 after 0 usecs

[  164.390352] calling  00:0a+ @ 2457, parent: pnp0
[  164.390357] call 00:0a+ returned 0 after 3 usecs

[  164.390361] calling  00:09+ @ 2457, parent: pnp0
[  164.496458] call 00:09+ returned 0 after 103500 usecs

[  164.496494] calling  00:05+ @ 2457, parent: pnp0
[  164.496511] call 00:05+ returned 0 after 14 usecs

dmesg output after the change:

[   58.707002] usb usb1: calling type pm ops @ 57, parent: 0000:00:1d.0
[   58.707641] usb usb1: call type pm ops returned 0 after 611 usecs

[   58.702014] system 00:0a: calling legacy bus pm ops @ 2173, parent: pnp0
[   58.702018] system 00:0a: call legacy bus pm ops returned 0 after 2 usecs

[   58.702023] tpm_tis 00:09: calling legacy bus pm ops @ 2173, parent: pnp0
[   58.806909] tpm_tis 00:09: call legacy bus pm ops returned 0 after 102425 usecs

[   58.806927] rtc_cmos 00:05: calling legacy bus pm ops @ 2173, parent: pnp0
[   58.806935] rtc_cmos 00:05: call legacy bus pm ops returned 0 after 5 usecs

Signed-off-by: Shuah Khan <shuah.kh@xxxxxxxxxxx>
---
 drivers/base/power/main.c |   44 +++++++++++++++++++++++++-------------------
 1 file changed, 25 insertions(+), 19 deletions(-)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 5a9b656..e8d2de7 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -157,13 +157,14 @@ void device_pm_move_last(struct device *dev)
 	list_move_tail(&dev->power.entry, &dpm_list);
 }
 
-static ktime_t initcall_debug_start(struct device *dev)
+static ktime_t initcall_debug_start(struct device *dev, char *info)
 {
 	ktime_t calltime = ktime_set(0, 0);
 
 	if (pm_print_times_enabled) {
-		pr_info("calling  %s+ @ %i, parent: %s\n",
-			dev_name(dev), task_pid_nr(current),
+		/* string in info has an extra space at the end */
+		dev_info(dev, "calling %s@ %i, parent: %s\n",
+			info, task_pid_nr(current),
 			dev->parent ? dev_name(dev->parent) : "none");
 		calltime = ktime_get();
 	}
@@ -172,14 +173,15 @@ static ktime_t initcall_debug_start(struct device *dev)
 }
 
 static void initcall_debug_report(struct device *dev, ktime_t calltime,
-				  int error)
+				  int error, char *info)
 {
 	ktime_t delta, rettime;
 
 	if (pm_print_times_enabled) {
 		rettime = ktime_get();
 		delta = ktime_sub(rettime, calltime);
-		pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
+		/* string in info has an extra space at the end */
+		dev_info(dev, "call %sreturned %d after %llu usecs\n", info,
 			error, (unsigned long long)ktime_to_ns(delta) >> 10);
 	}
 }
@@ -373,13 +375,13 @@ static int dpm_run_callback(pm_callback_t cb, struct device *dev,
 	if (!cb)
 		return 0;
 
-	calltime = initcall_debug_start(dev);
+	calltime = initcall_debug_start(dev, info);
 
 	pm_dev_dbg(dev, state, info);
 	error = cb(dev);
 	suspend_report_result(cb, error);
 
-	initcall_debug_report(dev, calltime, error);
+	initcall_debug_report(dev, calltime, error, info);
 
 	return error;
 }
@@ -1027,17 +1029,19 @@ EXPORT_SYMBOL_GPL(dpm_suspend_end);
  * @cb: Suspend callback to execute.
  */
 static int legacy_suspend(struct device *dev, pm_message_t state,
-			  int (*cb)(struct device *dev, pm_message_t state))
+			  int (*cb)(struct device *dev, pm_message_t state),
+			  char *info)
 {
 	int error;
 	ktime_t calltime;
 
-	calltime = initcall_debug_start(dev);
+	calltime = initcall_debug_start(dev, info);
 
+	pm_dev_dbg(dev, state, info);
 	error = cb(dev, state);
 	suspend_report_result(cb, error);
 
-	initcall_debug_report(dev, calltime, error);
+	initcall_debug_report(dev, calltime, error, info);
 
 	return error;
 }
@@ -1079,43 +1083,45 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 	device_lock(dev);
 
 	if (dev->pm_domain) {
-		info = "power domain ";
+		info = "power domain pm ops ";
 		callback = pm_op(&dev->pm_domain->ops, state);
 		goto Run;
 	}
 
 	if (dev->type && dev->type->pm) {
-		info = "type ";
+		info = "type pm ops ";
 		callback = pm_op(dev->type->pm, state);
 		goto Run;
 	}
 
 	if (dev->class) {
 		if (dev->class->pm) {
-			info = "class ";
+			info = "class pm ops ";
 			callback = pm_op(dev->class->pm, state);
 			goto Run;
 		} else if (dev->class->suspend) {
-			pm_dev_dbg(dev, state, "legacy class ");
-			error = legacy_suspend(dev, state, dev->class->suspend);
+			info = "legacy class pm ops ";
+			error = legacy_suspend(dev, state, dev->class->suspend,
+				info);
 			goto End;
 		}
 	}
 
 	if (dev->bus) {
 		if (dev->bus->pm) {
-			info = "bus ";
+			info = "bus pm ops ";
 			callback = pm_op(dev->bus->pm, state);
 		} else if (dev->bus->suspend) {
-			pm_dev_dbg(dev, state, "legacy bus ");
-			error = legacy_suspend(dev, state, dev->bus->suspend);
+			info = "legacy bus pm ops ";
+			error = legacy_suspend(dev, state, dev->bus->suspend,
+				info);
 			goto End;
 		}
 	}
 
  Run:
 	if (!callback && dev->driver && dev->driver->pm) {
-		info = "driver ";
+		info = "driver pm ops ";
 		callback = pm_op(dev->driver->pm, state);
 	}
 
-- 
1.7.10.4

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