From: Colin Cross <ccross@android.com>
Date: Wed, 10 Aug 2011 16:41:59 +0000 (-0500)
Subject: PM: runtime: add might_sleep to PM runtime functions
X-Git-Tag: firefly_0821_release~7613^2~287
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b1d0d5fe07a4c96d791f3126bbfc8d0131d1aa32;p=firefly-linux-kernel-4.4.55.git

PM: runtime: add might_sleep to PM runtime functions

The list of functions that can be called in atomic context is
non-intuitive (pm_runtime_put_sync can not, but
pm_runtime_put_sync_suspend can, if pm_runtime_irq_safe has
been called?).  The code is actively misleading - the entry
points all start with spin_lock_irqsave, suggesting they
are safe to call in atomic context, but may later
enable interrupts.

Add might_sleep_if to all the __pm_runtime_* entry points
to enforce correct usage.

Also add pm_runtime_put_sync_autosuspend to the list of
functions that can be called in atomic context.

Change-Id: Icac17a10d77c64d44bd2761a91a588dfd1d0c6f0
Signed-off-by: Colin Cross <ccross@android.com>
---

diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index b24875b1ced5..22852b3cf49f 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -469,6 +469,7 @@ pm_runtime_autosuspend()
 pm_runtime_resume()
 pm_runtime_get_sync()
 pm_runtime_put_sync_suspend()
+pm_runtime_put_sync_autosuspend()
 
 5. Run-time PM Initialization, Device Probing and Removal
 
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 0d4587b15c55..577f4fd16480 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -732,6 +732,8 @@ int __pm_runtime_idle(struct device *dev, int rpmflags)
 	unsigned long flags;
 	int retval;
 
+	might_sleep_if(!(rpmflags & RPM_ASYNC));
+
 	if (rpmflags & RPM_GET_PUT) {
 		if (!atomic_dec_and_test(&dev->power.usage_count))
 			return 0;
@@ -761,6 +763,8 @@ int __pm_runtime_suspend(struct device *dev, int rpmflags)
 	unsigned long flags;
 	int retval;
 
+	might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
+
 	if (rpmflags & RPM_GET_PUT) {
 		if (!atomic_dec_and_test(&dev->power.usage_count))
 			return 0;
@@ -789,6 +793,8 @@ int __pm_runtime_resume(struct device *dev, int rpmflags)
 	unsigned long flags;
 	int retval;
 
+	might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
+
 	if (rpmflags & RPM_GET_PUT)
 		atomic_inc(&dev->power.usage_count);
 
@@ -978,6 +984,7 @@ EXPORT_SYMBOL_GPL(pm_runtime_barrier);
  */
 void __pm_runtime_disable(struct device *dev, bool check_resume)
 {
+	might_sleep();
 	spin_lock_irq(&dev->power.lock);
 
 	if (dev->power.disable_depth > 0) {
@@ -1184,6 +1191,8 @@ void __pm_runtime_use_autosuspend(struct device *dev, bool use)
 {
 	int old_delay, old_use;
 
+	might_sleep();
+
 	spin_lock_irq(&dev->power.lock);
 	old_delay = dev->power.autosuspend_delay;
 	old_use = dev->power.use_autosuspend;