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authorRafael J. Wysocki <rjw@sisk.pl>2011-09-27 21:54:52 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2011-09-27 21:54:52 +0200
commitad3c36a534bc7b945d7bffdda1c62e13bf93489a (patch)
tree5f7520f575891716577de33176713b8cb13a22d5 /drivers/base
parent30b1a7a32ca48fd8758f8ca44d60deebc0aa3d72 (diff)
downloadop-kernel-dev-ad3c36a534bc7b945d7bffdda1c62e13bf93489a.zip
op-kernel-dev-ad3c36a534bc7b945d7bffdda1c62e13bf93489a.tar.gz
PM / Runtime: Don't run callbacks under lock for power.irq_safe set
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. This change requires the code checking if the device's runtime PM status is RPM_SUSPENDING or RPM_RESUMING to be modified too, to take the power.irq_safe set case into account (that code wasn't reachable before with power.irq_safe set, because it's executed with the device's power.lock held). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Kevin Hilman <khilman@ti.com>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/power/runtime.c68
1 files changed, 46 insertions, 22 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 04e18ab..aecb2a8 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -155,6 +155,31 @@ static int rpm_check_suspend_allowed(struct device *dev)
}
/**
+ * __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, int rpmflags)
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, int rpmflags)
* @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 *dev, int rpmflags)
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, int rpmflags)
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,
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