PM-runtime: add tracepoints for usage_count changes

Add tracepoints to remaining places where device's power.usage_count
is changed.

This helps debugging where and why autosuspend is prevented.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 48616f358854a4562222877b5dd779e4d1434460..16134a69bf6f5eac2d20f215a81a037e57ef3e7d 100644 (file)
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1006,8 +1006,10 @@ int __pm_runtime_idle(struct device *dev, int rpmflags)
        int retval;
 
        if (rpmflags & RPM_GET_PUT) {
-               if (!atomic_dec_and_test(&dev->power.usage_count))
+               if (!atomic_dec_and_test(&dev->power.usage_count)) {
+                       trace_rpm_usage_rcuidle(dev, rpmflags);
                        return 0;
+               }
        }
 
        might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
@@ -1038,8 +1040,10 @@ int __pm_runtime_suspend(struct device *dev, int rpmflags)
        int retval;
 
        if (rpmflags & RPM_GET_PUT) {
-               if (!atomic_dec_and_test(&dev->power.usage_count))
+               if (!atomic_dec_and_test(&dev->power.usage_count)) {
+                       trace_rpm_usage_rcuidle(dev, rpmflags);
                        return 0;
+               }
        }
 
        might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
@@ -1101,6 +1105,7 @@ int pm_runtime_get_if_in_use(struct device *dev)
        retval = dev->power.disable_depth > 0 ? -EINVAL :
                dev->power.runtime_status == RPM_ACTIVE
                        && atomic_inc_not_zero(&dev->power.usage_count);
+       trace_rpm_usage_rcuidle(dev, 0);
        spin_unlock_irqrestore(&dev->power.lock, flags);
        return retval;
 }
@@ -1434,6 +1439,8 @@ void pm_runtime_allow(struct device *dev)
        dev->power.runtime_auto = true;
        if (atomic_dec_and_test(&dev->power.usage_count))
                rpm_idle(dev, RPM_AUTO | RPM_ASYNC);
+       else
+               trace_rpm_usage_rcuidle(dev, RPM_AUTO | RPM_ASYNC);
 
  out:
        spin_unlock_irq(&dev->power.lock);
@@ -1501,6 +1508,8 @@ static void update_autosuspend(struct device *dev, int old_delay, int old_use)
                if (!old_use || old_delay >= 0) {
                        atomic_inc(&dev->power.usage_count);
                        rpm_resume(dev, 0);
+               } else {
+                       trace_rpm_usage_rcuidle(dev, 0);
                }
        }
 

diff --git a/include/trace/events/rpm.h b/include/trace/events/rpm.h
index 26927a560eabca1a880d9d031b610588bbb6e3ea..3c716214dab1a36543cd8234798f21eda774d09b 100644 (file)
--- a/include/trace/events/rpm.h
+++ b/include/trace/events/rpm.h
@@ -74,6 +74,12 @@ DEFINE_EVENT(rpm_internal, rpm_idle,
 
        TP_ARGS(dev, flags)
 );
+DEFINE_EVENT(rpm_internal, rpm_usage,
+
+       TP_PROTO(struct device *dev, int flags),
+
+       TP_ARGS(dev, flags)
+);
 
 TRACE_EVENT(rpm_return_int,
        TP_PROTO(struct device *dev, unsigned long ip, int ret),