[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 f8f5055..2646897 100644
--- a/drivers/base/power/resume.c
+++ b/drivers/base/power/resume.c
@@ -22,8 +22,17 @@
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 d1e023f..9797990 100644
--- a/drivers/base/power/shutdown.c
+++ b/drivers/base/power/shutdown.c
@@ -25,8 +25,10 @@
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 @@
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 a0b5cf6..0ec44ef 100644
--- a/drivers/base/power/suspend.c
+++ b/drivers/base/power/suspend.c
@@ -39,12 +39,25 @@
{
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 7960ddf..4cdebc9 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -156,14 +156,14 @@
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);