From: David Brownell <david-b@pacbell.net>
Date: Mon, 9 May 2005 15:07:00 +0000 (-0700)
Subject: [PATCH] Driver Core: pm diagnostics update, check for errors
X-Git-Tag: v2.6.12-rc5~49^2~1
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=82428b62aa6294ea640c7e920a9224ecaf46db65;p=linux-2.6

[PATCH] Driver Core: pm diagnostics update, check for errors

This patch includes various tweaks in the messaging that appears during
system pm state transitions:

  * Warn about certain illegal calls in the device tree, like resuming
    child before parent or suspending parent before child.  This could
    happen easily enough through sysfs, or in some cases when drivers
    use device_pm_set_parent().

  * Be more consistent about dev_dbg() tracing ... do it for resume() and
    shutdown() too, and never if the driver doesn't have that method.

  * Say which type of system sleep state is being entered.

Except for the warnings, these only affect debug messaging.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/base/power/resume.c b/drivers/base/power/resume.c
index f8f5055754..26468971ef 100644
--- a/drivers/base/power/resume.c
+++ b/drivers/base/power/resume.c
@@ -22,8 +22,17 @@ extern int sysdev_resume(void);
 
 int resume_device(struct device * dev)
 {
-	if (dev->bus && dev->bus->resume)
+	if (dev->power.pm_parent
+			&& dev->power.pm_parent->power.power_state) {
+		dev_err(dev, "PM: resume from %d, parent %s still %d\n",
+			dev->power.power_state,
+			dev->power.pm_parent->bus_id,
+			dev->power.pm_parent->power.power_state);
+	}
+	if (dev->bus && dev->bus->resume) {
+		dev_dbg(dev,"resuming\n");
 		return dev->bus->resume(dev);
+	}
 	return 0;
 }
 
diff --git a/drivers/base/power/shutdown.c b/drivers/base/power/shutdown.c
index d1e023fbe1..97979901c1 100644
--- a/drivers/base/power/shutdown.c
+++ b/drivers/base/power/shutdown.c
@@ -25,8 +25,10 @@ int device_detach_shutdown(struct device * dev)
 		return 0;
 
 	if (dev->detach_state == DEVICE_PM_OFF) {
-		if (dev->driver && dev->driver->shutdown)
+		if (dev->driver && dev->driver->shutdown) {
+			dev_dbg(dev, "shutdown\n");
 			dev->driver->shutdown(dev);
+		}
 		return 0;
 	}
 	return dpm_runtime_suspend(dev, dev->detach_state);
@@ -52,13 +54,12 @@ void device_shutdown(void)
 	struct device * dev;
 
 	down_write(&devices_subsys.rwsem);
-	list_for_each_entry_reverse(dev, &devices_subsys.kset.list, kobj.entry) {
-		pr_debug("shutting down %s: ", dev->bus_id);
+	list_for_each_entry_reverse(dev, &devices_subsys.kset.list,
+				kobj.entry) {
 		if (dev->driver && dev->driver->shutdown) {
-			pr_debug("Ok\n");
+			dev_dbg(dev, "shutdown\n");
 			dev->driver->shutdown(dev);
-		} else
-			pr_debug("Ignored.\n");
+		}
 	}
 	up_write(&devices_subsys.rwsem);
 
diff --git a/drivers/base/power/suspend.c b/drivers/base/power/suspend.c
index a0b5cf689e..0ec44ef840 100644
--- a/drivers/base/power/suspend.c
+++ b/drivers/base/power/suspend.c
@@ -39,12 +39,25 @@ int suspend_device(struct device * dev, pm_message_t state)
 {
 	int error = 0;
 
-	dev_dbg(dev, "suspending\n");
+	if (dev->power.power_state) {
+		dev_dbg(dev, "PM: suspend %d-->%d\n",
+			dev->power.power_state, state);
+	}
+	if (dev->power.pm_parent
+			&& dev->power.pm_parent->power.power_state) {
+		dev_err(dev,
+			"PM: suspend %d->%d, parent %s already %d\n",
+			dev->power.power_state, state,
+			dev->power.pm_parent->bus_id,
+			dev->power.pm_parent->power.power_state);
+	}
 
 	dev->power.prev_state = dev->power.power_state;
 
-	if (dev->bus && dev->bus->suspend && !dev->power.power_state)
+	if (dev->bus && dev->bus->suspend && !dev->power.power_state) {
+		dev_dbg(dev, "suspending\n");
 		error = dev->bus->suspend(dev, state);
+	}
 
 	return error;
 }
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 7960ddf04a..4cdebc972f 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -156,14 +156,14 @@ static int enter_state(suspend_state_t state)
 		goto Unlock;
 	}
 
-	pr_debug("PM: Preparing system for suspend\n");
+	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
 	if ((error = suspend_prepare(state)))
 		goto Unlock;
 
-	pr_debug("PM: Entering state.\n");
+	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
 	error = suspend_enter(state);
 
-	pr_debug("PM: Finishing up.\n");
+	pr_debug("PM: Finishing wakeup.\n");
 	suspend_finish(state);
  Unlock:
 	up(&pm_sem);