[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>

1 files changed, 7 insertions, 6 deletions

diff --git a/drivers/base/power/shutdown.c b/drivers/base/power/shutdown.c
index d1e023fbe169..97979901c149 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);