Commit 82428b62 authored by David Brownell's avatar David Brownell Committed by Greg KH
Browse files

[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: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent ff0d2f90

drivers/base/power/resume.c

+10 −1
Original line number Diff line number Diff line
@@ -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;

}

drivers/base/power/shutdown.c

+7 −6
Original line number Diff line number Diff line
@@ -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);

drivers/base/power/suspend.c

+15 −2
Original line number Diff line number Diff line
@@ -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;

}

kernel/power/main.c

+3 −3
Original line number Diff line number Diff line
@@ -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);

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