From 2fb242adcaab5defa2f208775ac4f181ac998fdd Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Sun, 9 Oct 2011 11:40:25 +0800 Subject: PM / Runtime: Update document about callbacks Support for device power domains has been introduced in commit 9659cc0678b954f187290c6e8b247a673c5d37e1 (PM: Make system-wide PM and runtime PM treat subsystems consistently), also power domain callbacks will take precedence over subsystem ones from commit 4d27e9dcff00a6425d779b065ec8892e4f391661(PM: Make power domain callbacks take precedence over subsystem ones). So update part of "Device Runtime PM Callbacks" in Documentation/power/runtime_pm.txt. Signed-off-by: Ming Lei Signed-off-by: Rafael J. Wysocki diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt index 1750740..f670836 100644 --- a/Documentation/power/runtime_pm.txt +++ b/Documentation/power/runtime_pm.txt @@ -43,13 +43,18 @@ struct dev_pm_ops { ... }; -The ->runtime_suspend(), ->runtime_resume() and ->runtime_idle() callbacks are -executed by the PM core for either the device type, or the class (if the device -type's struct dev_pm_ops object does not exist), or the bus type (if the -device type's and class' struct dev_pm_ops objects do not exist) of the given -device (this allows device types to override callbacks provided by bus types or -classes if necessary). The bus type, device type and class callbacks are -referred to as subsystem-level callbacks in what follows. +The ->runtime_suspend(), ->runtime_resume() and ->runtime_idle() callbacks +are executed by the PM core for either the power domain, or the device type +(if the device power domain's struct dev_pm_ops does not exist), or the class +(if the device power domain's and type's struct dev_pm_ops object does not +exist), or the bus type (if the device power domain's, type's and class' +struct dev_pm_ops objects do not exist) of the given device, so the priority +order of callbacks from high to low is that power domain callbacks, device +type callbacks, class callbacks and bus type callbacks, and the high priority +one will take precedence over low priority one. The bus type, device type and +class callbacks are referred to as subsystem-level callbacks in what follows, +and generally speaking, the power domain callbacks are used for representing +power domains within a SoC. By default, the callbacks are always invoked in process context with interrupts enabled. However, subsystems can use the pm_runtime_irq_safe() helper function -- cgit v0.10.2 From 47d8f0bac0fda4c15a030f92cd6da6c6bed87459 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 12 Oct 2011 11:53:32 +0800 Subject: PM / Runtime: Fix kerneldoc comment for rpm_suspend() This patch fix kerneldoc comments for rpm_suspend(): - 'Cancel a pending idle notification' should be put before, also should be changed to 'Cancel a pending idle notification, autosuspend or suspend'. - idle notification for the device after succeeding suspend has been removed, so update the comment accordingly. [rjw: Modified the subject and changelog slightly.] Signed-off-by: Ming Lei Signed-off-by: Rafael J. Wysocki diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 7a6fb5e..aa23a64 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -286,14 +286,16 @@ static int rpm_callback(int (*cb)(struct device *), struct device *dev) * @dev: Device to suspend. * @rpmflags: Flag bits. * - * Check if the device's runtime PM status allows it to be suspended. If - * another suspend has been started earlier, either return immediately or wait - * for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC flags. Cancel a - * pending idle notification. If the RPM_ASYNC flag is set then queue a - * suspend request; otherwise run the ->runtime_suspend() callback directly. - * If a deferred resume was requested while the callback was running then carry - * it out; otherwise send an idle notification for the device (if the suspend - * failed) or for its parent (if the suspend succeeded). + * Check if the device's runtime PM status allows it to be suspended. + * Cancel a pending idle notification, autosuspend or suspend. If + * another suspend has been started earlier, either return immediately + * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC + * flags. If the RPM_ASYNC flag is set then queue a suspend request; + * otherwise run the ->runtime_suspend() callback directly. If a deferred + * resume was requested while the callback was running then carry it out; + * otherwise send an idle notification for its parent (if the suspend + * succeeded and both ignore_children of parent->power and irq_safe of + * dev->power are not set). * * This function must be called under dev->power.lock with interrupts disabled. */ -- cgit v0.10.2 From 857b36c7b038ac56a882ee914df93e5985443074 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 12 Oct 2011 22:59:33 +0200 Subject: PM / Runtime: Handle .runtime_suspend() failure correctly If .runtime_suspend() returns -EAGAIN or -EBUSY, the device should still be in ACTIVE state, so it is not necessary to send an idle notification to its parent. If .runtime_suspend() returns other fatal failure, it doesn't make sense to send idle notification to its parent. Skip parent idle notification when failure is returned from .runtime_suspend() and update comments in rpm_suspend() to reflect that change. [rjw: Modified the subject and changelog slightly.] Signed-off-by: Ming Lei Signed-off-by: Rafael J. Wysocki diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index aa23a64..6bb3aaf 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -291,11 +291,11 @@ static int rpm_callback(int (*cb)(struct device *), struct device *dev) * another suspend has been started earlier, either return immediately * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC * flags. If the RPM_ASYNC flag is set then queue a suspend request; - * otherwise run the ->runtime_suspend() callback directly. If a deferred - * resume was requested while the callback was running then carry it out; - * otherwise send an idle notification for its parent (if the suspend - * succeeded and both ignore_children of parent->power and irq_safe of - * dev->power are not set). + * otherwise run the ->runtime_suspend() callback directly. When + * ->runtime_suspend succeeded, if a deferred resume was requested while + * the callback was running then carry it out, otherwise send an idle + * notification for its parent (if the suspend succeeded and both + * ignore_children of parent->power and irq_safe of dev->power are not set). * * This function must be called under dev->power.lock with interrupts disabled. */ @@ -420,15 +420,16 @@ static int rpm_suspend(struct device *dev, int rpmflags) dev->power.runtime_error = 0; else pm_runtime_cancel_pending(dev); - } else { + wake_up_all(&dev->power.wait_queue); + goto out; + } no_callback: - __update_runtime_status(dev, RPM_SUSPENDED); - pm_runtime_deactivate_timer(dev); + __update_runtime_status(dev, RPM_SUSPENDED); + pm_runtime_deactivate_timer(dev); - if (dev->parent) { - parent = dev->parent; - atomic_add_unless(&parent->power.child_count, -1, 0); - } + if (dev->parent) { + parent = dev->parent; + atomic_add_unless(&parent->power.child_count, -1, 0); } wake_up_all(&dev->power.wait_queue); -- cgit v0.10.2