Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | [PATCH 2/3] PM / Runtime: Don't run callbacks under lock for power.irq_safe set | Date | Sat, 24 Sep 2011 23:25:53 +0200 |
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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,
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