lkml.org 
[lkml]   [2011]   [Sep]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/3] PM / Runtime: Don't run callbacks under lock for power.irq_safe set
Date
From: Rafael J. Wysocki <rjw@sisk.pl>

The rpm_suspend() and rpm_resume() routines execute subsystem or PM
domain callbacks under power.lock if power.irq_safe is set for the
given device. This is inconsistent with that rpm_idle() does after
commit 02b2677 (PM / Runtime: Allow _put_sync() from
interrupts-disabled context) and is problematic for subsystems and PM
domains wanting to use power.lock for synchronization in their
runtime PM callbacks.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
drivers/base/power/runtime.c | 68 +++++++++++++++++++++++++++++--------------
1 file changed, 46 insertions(+), 22 deletions(-)
Index: linux/drivers/base/power/runtime.c
===================================================================
--- linux.orig/drivers/base/power/runtime.c
+++ linux/drivers/base/power/runtime.c
@@ -155,6 +155,31 @@ static int rpm_check_suspend_allowed(str
}

/**
+ * __rpm_callback - Run a given runtime PM callback for a given device.
+ * @cb: Runtime PM callback to run.
+ * @dev: Device to run the callback for.
+ */
+static int __rpm_callback(int (*cb)(struct device *), struct device *dev)
+ __releases(&dev->power.lock) __acquires(&dev->power.lock)
+{
+ int retval;
+
+ if (dev->power.irq_safe)
+ spin_unlock(&dev->power.lock);
+ else
+ spin_unlock_irq(&dev->power.lock);
+
+ retval = cb(dev);
+
+ if (dev->power.irq_safe)
+ spin_lock(&dev->power.lock);
+ else
+ spin_lock_irq(&dev->power.lock);
+
+ return retval;
+}
+
+/**
* rpm_idle - Notify device bus type if the device can be suspended.
* @dev: Device to notify the bus type about.
* @rpmflags: Flag bits.
@@ -225,19 +250,8 @@ static int rpm_idle(struct device *dev,
else
callback = NULL;

- if (callback) {
- if (dev->power.irq_safe)
- spin_unlock(&dev->power.lock);
- else
- spin_unlock_irq(&dev->power.lock);
-
- callback(dev);
-
- if (dev->power.irq_safe)
- spin_lock(&dev->power.lock);
- else
- spin_lock_irq(&dev->power.lock);
- }
+ if (callback)
+ __rpm_callback(callback, dev);

dev->power.idle_notification = false;
wake_up_all(&dev->power.wait_queue);
@@ -252,22 +266,14 @@ static int rpm_idle(struct device *dev,
* @dev: Device to run the callback for.
*/
static int rpm_callback(int (*cb)(struct device *), struct device *dev)
- __releases(&dev->power.lock) __acquires(&dev->power.lock)
{
int retval;

if (!cb)
return -ENOSYS;

- if (dev->power.irq_safe) {
- retval = cb(dev);
- } else {
- spin_unlock_irq(&dev->power.lock);
-
- retval = cb(dev);
+ retval = __rpm_callback(cb, dev);

- spin_lock_irq(&dev->power.lock);
- }
dev->power.runtime_error = retval;
return retval != -EACCES ? retval : -EIO;
}
@@ -347,6 +353,15 @@ static int rpm_suspend(struct device *de
goto out;
}

+ if (dev->power.irq_safe) {
+ spin_unlock(&dev->power.lock);
+
+ cpu_relax();
+
+ spin_lock(&dev->power.lock);
+ goto repeat;
+ }
+
/* Wait for the other suspend running in parallel with us. */
for (;;) {
prepare_to_wait(&dev->power.wait_queue, &wait,
@@ -496,6 +511,15 @@ static int rpm_resume(struct device *dev
goto out;
}

+ if (dev->power.irq_safe) {
+ spin_unlock(&dev->power.lock);
+
+ cpu_relax();
+
+ spin_lock(&dev->power.lock);
+ goto repeat;
+ }
+
/* Wait for the operation carried out in parallel with us. */
for (;;) {
prepare_to_wait(&dev->power.wait_queue, &wait,


\
 
 \ /
  Last update: 2011-09-24 23:29    [from the cache]
©2003-2011 Jasper Spaans