From 9659cc0678b954f187290c6e8b247a673c5d37e1 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 18 Feb 2011 23:20:21 +0100 Subject: [PATCH] PM: Make system-wide PM and runtime PM treat subsystems consistently The code handling system-wide power transitions (eg. suspend-to-RAM) can in theory execute callbacks provided by the device's bus type, device type and class in each phase of the power transition. In turn, the runtime PM core code only calls one of those callbacks at a time, preferring bus type callbacks to device type or class callbacks and device type callbacks to class callbacks. It seems reasonable to make them both behave in the same way in that respect. Moreover, even though a device may belong to two subsystems (eg. bus type and device class) simultaneously, in practice power management callbacks for system-wide power transitions are always provided by only one of them (ie. if the bus type callbacks are defined, the device class ones are not and vice versa). Thus it is possible to modify the code handling system-wide power transitions so that it follows the core runtime PM code (ie. treats the subsystem callbacks as mutually exclusive). On the other hand, the core runtime PM code will choose to execute, for example, a runtime suspend callback provided by the device type even if the bus type's struct dev_pm_ops object exists, but the runtime_suspend pointer in it happens to be NULL. This is confusing, because it may lead to the execution of callbacks from different subsystems during different operations (eg. the bus type suspend callback may be executed during runtime suspend of the device, while the device type callback will be executed during system suspend). Make all of the power management code treat subsystem callbacks in a consistent way, such that: (1) If the device's type is defined (eg. dev->type is not NULL) and its pm pointer is not NULL, the callbacks from dev->type->pm will be used. (2) If dev->type is NULL or dev->type->pm is NULL, but the device's class is defined (eg. dev->class is not NULL) and its pm pointer is not NULL, the callbacks from dev->class->pm will be used. (3) If dev->type is NULL or dev->type->pm is NULL and dev->class is NULL or dev->class->pm is NULL, the callbacks from dev->bus->pm will be used provided that both dev->bus and dev->bus->pm are not NULL. Signed-off-by: Rafael J. Wysocki Acked-by: Kevin Hilman Reasoning-sounds-sane-to: Grant Likely Acked-by: Greg Kroah-Hartman --- Documentation/power/devices.txt | 29 +++--- Documentation/power/runtime_pm.txt | 13 +-- drivers/base/power/main.c | 150 ++++++++++++----------------- drivers/base/power/runtime.c | 18 ++-- 4 files changed, 92 insertions(+), 118 deletions(-) diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index df1a5cb10c4..f023ba6bba6 100644 --- a/Documentation/power/devices.txt +++ b/Documentation/power/devices.txt @@ -249,23 +249,18 @@ various phases always run after tasks have been frozen and before they are unfrozen. Furthermore, the *_noirq phases run at a time when IRQ handlers have been disabled (except for those marked with the IRQ_WAKEUP flag). -Most phases use bus, type, and class callbacks (that is, methods defined in -dev->bus->pm, dev->type->pm, and dev->class->pm). The prepare and complete -phases are exceptions; they use only bus callbacks. When multiple callbacks -are used in a phase, they are invoked in the order: during -power-down transitions and in the opposite order during power-up transitions. -For example, during the suspend phase the PM core invokes - - dev->class->pm.suspend(dev); - dev->type->pm.suspend(dev); - dev->bus->pm.suspend(dev); - -before moving on to the next device, whereas during the resume phase the core -invokes - - dev->bus->pm.resume(dev); - dev->type->pm.resume(dev); - dev->class->pm.resume(dev); +All phases use bus, type, or class callbacks (that is, methods defined in +dev->bus->pm, dev->type->pm, or dev->class->pm). These callbacks are mutually +exclusive, so if the device type provides a struct dev_pm_ops object pointed to +by its pm field (i.e. both dev->type and dev->type->pm are defined), the +callbacks included in that object (i.e. dev->type->pm) will be used. Otherwise, +if the class provides a struct dev_pm_ops object pointed to by its pm field +(i.e. both dev->class and dev->class->pm are defined), the PM core will use the +callbacks from that object (i.e. dev->class->pm). Finally, if the pm fields of +both the device type and class objects are NULL (or those objects do not exist), +the callbacks provided by the bus (that is, the callbacks from dev->bus->pm) +will be used (this allows device types to override callbacks provided by bus +types or classes if necessary). These callbacks may in turn invoke device- or driver-specific methods stored in dev->driver->pm, but they don't have to. diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt index ffe55ffa540..654097b130b 100644 --- a/Documentation/power/runtime_pm.txt +++ b/Documentation/power/runtime_pm.txt @@ -1,6 +1,6 @@ Run-time Power Management Framework for I/O Devices -(C) 2009 Rafael J. Wysocki , Novell Inc. +(C) 2009-2011 Rafael J. Wysocki , Novell Inc. (C) 2010 Alan Stern 1. Introduction @@ -44,11 +44,12 @@ struct dev_pm_ops { }; The ->runtime_suspend(), ->runtime_resume() and ->runtime_idle() callbacks are -executed by the PM core for either the bus type, or device type (if the bus -type's callback is not defined), or device class (if the bus type's and device -type's callbacks are not defined) of given device. The bus type, device type -and device class callbacks are referred to as subsystem-level callbacks in what -follows. +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. By default, the callbacks are always invoked in process context with interrupts enabled. However, subsystems can use the pm_runtime_irq_safe() helper function diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 05b989139b5..052dc53eef3 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -428,26 +428,17 @@ static int device_resume_noirq(struct device *dev, pm_message_t state) pm_noirq_op(dev, &dev->pwr_domain->ops, state); } - if (dev->bus && dev->bus->pm) { - pm_dev_dbg(dev, state, "EARLY "); - error = pm_noirq_op(dev, dev->bus->pm, state); - if (error) - goto End; - } - if (dev->type && dev->type->pm) { pm_dev_dbg(dev, state, "EARLY type "); error = pm_noirq_op(dev, dev->type->pm, state); - if (error) - goto End; - } - - if (dev->class && dev->class->pm) { + } else if (dev->class && dev->class->pm) { pm_dev_dbg(dev, state, "EARLY class "); error = pm_noirq_op(dev, dev->class->pm, state); + } else if (dev->bus && dev->bus->pm) { + pm_dev_dbg(dev, state, "EARLY "); + error = pm_noirq_op(dev, dev->bus->pm, state); } -End: TRACE_RESUME(error); return error; } @@ -528,36 +519,34 @@ static int device_resume(struct device *dev, pm_message_t state, bool async) pm_op(dev, &dev->pwr_domain->ops, state); } - if (dev->bus) { - if (dev->bus->pm) { - pm_dev_dbg(dev, state, ""); - error = pm_op(dev, dev->bus->pm, state); - } else if (dev->bus->resume) { - pm_dev_dbg(dev, state, "legacy "); - error = legacy_resume(dev, dev->bus->resume); - } - if (error) - goto End; - } - - if (dev->type) { - if (dev->type->pm) { - pm_dev_dbg(dev, state, "type "); - error = pm_op(dev, dev->type->pm, state); - } - if (error) - goto End; + if (dev->type && dev->type->pm) { + pm_dev_dbg(dev, state, "type "); + error = pm_op(dev, dev->type->pm, state); + goto End; } if (dev->class) { if (dev->class->pm) { pm_dev_dbg(dev, state, "class "); error = pm_op(dev, dev->class->pm, state); + goto End; } else if (dev->class->resume) { pm_dev_dbg(dev, state, "legacy class "); error = legacy_resume(dev, dev->class->resume); + goto End; } } + + if (dev->bus) { + if (dev->bus->pm) { + pm_dev_dbg(dev, state, ""); + error = pm_op(dev, dev->bus->pm, state); + } else if (dev->bus->resume) { + pm_dev_dbg(dev, state, "legacy "); + error = legacy_resume(dev, dev->bus->resume); + } + } + End: device_unlock(dev); complete_all(&dev->power.completion); @@ -644,19 +633,18 @@ static void device_complete(struct device *dev, pm_message_t state) dev->pwr_domain->ops.complete(dev); } - if (dev->class && dev->class->pm && dev->class->pm->complete) { - pm_dev_dbg(dev, state, "completing class "); - dev->class->pm->complete(dev); - } - - if (dev->type && dev->type->pm && dev->type->pm->complete) { + if (dev->type && dev->type->pm) { pm_dev_dbg(dev, state, "completing type "); - dev->type->pm->complete(dev); - } - - if (dev->bus && dev->bus->pm && dev->bus->pm->complete) { + if (dev->type->pm->complete) + dev->type->pm->complete(dev); + } else if (dev->class && dev->class->pm) { + pm_dev_dbg(dev, state, "completing class "); + if (dev->class->pm->complete) + dev->class->pm->complete(dev); + } else if (dev->bus && dev->bus->pm) { pm_dev_dbg(dev, state, "completing "); - dev->bus->pm->complete(dev); + if (dev->bus->pm->complete) + dev->bus->pm->complete(dev); } device_unlock(dev); @@ -741,27 +729,23 @@ static pm_message_t resume_event(pm_message_t sleep_state) */ static int device_suspend_noirq(struct device *dev, pm_message_t state) { - int error = 0; - - if (dev->class && dev->class->pm) { - pm_dev_dbg(dev, state, "LATE class "); - error = pm_noirq_op(dev, dev->class->pm, state); - if (error) - goto End; - } + int error; if (dev->type && dev->type->pm) { pm_dev_dbg(dev, state, "LATE type "); error = pm_noirq_op(dev, dev->type->pm, state); if (error) - goto End; - } - - if (dev->bus && dev->bus->pm) { + return error; + } else if (dev->class && dev->class->pm) { + pm_dev_dbg(dev, state, "LATE class "); + error = pm_noirq_op(dev, dev->class->pm, state); + if (error) + return error; + } else if (dev->bus && dev->bus->pm) { pm_dev_dbg(dev, state, "LATE "); error = pm_noirq_op(dev, dev->bus->pm, state); if (error) - goto End; + return error; } if (dev->pwr_domain) { @@ -769,8 +753,7 @@ static int device_suspend_noirq(struct device *dev, pm_message_t state) pm_noirq_op(dev, &dev->pwr_domain->ops, state); } -End: - return error; + return 0; } /** @@ -857,25 +840,22 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) goto End; } + if (dev->type && dev->type->pm) { + pm_dev_dbg(dev, state, "type "); + error = pm_op(dev, dev->type->pm, state); + goto Domain; + } + if (dev->class) { if (dev->class->pm) { pm_dev_dbg(dev, state, "class "); error = pm_op(dev, dev->class->pm, state); + goto Domain; } else if (dev->class->suspend) { pm_dev_dbg(dev, state, "legacy class "); error = legacy_suspend(dev, state, dev->class->suspend); + goto Domain; } - if (error) - goto End; - } - - if (dev->type) { - if (dev->type->pm) { - pm_dev_dbg(dev, state, "type "); - error = pm_op(dev, dev->type->pm, state); - } - if (error) - goto End; } if (dev->bus) { @@ -886,11 +866,10 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) pm_dev_dbg(dev, state, "legacy "); error = legacy_suspend(dev, state, dev->bus->suspend); } - if (error) - goto End; } - if (dev->pwr_domain) { + Domain: + if (!error && dev->pwr_domain) { pm_dev_dbg(dev, state, "power domain "); pm_op(dev, &dev->pwr_domain->ops, state); } @@ -985,28 +964,27 @@ static int device_prepare(struct device *dev, pm_message_t state) device_lock(dev); - if (dev->bus && dev->bus->pm && dev->bus->pm->prepare) { - pm_dev_dbg(dev, state, "preparing "); - error = dev->bus->pm->prepare(dev); - suspend_report_result(dev->bus->pm->prepare, error); - if (error) - goto End; - } - - if (dev->type && dev->type->pm && dev->type->pm->prepare) { + if (dev->type && dev->type->pm) { pm_dev_dbg(dev, state, "preparing type "); - error = dev->type->pm->prepare(dev); + if (dev->type->pm->prepare) + error = dev->type->pm->prepare(dev); suspend_report_result(dev->type->pm->prepare, error); if (error) goto End; - } - - if (dev->class && dev->class->pm && dev->class->pm->prepare) { + } else if (dev->class && dev->class->pm) { pm_dev_dbg(dev, state, "preparing class "); - error = dev->class->pm->prepare(dev); + if (dev->class->pm->prepare) + error = dev->class->pm->prepare(dev); suspend_report_result(dev->class->pm->prepare, error); if (error) goto End; + } else if (dev->bus && dev->bus->pm) { + pm_dev_dbg(dev, state, "preparing "); + if (dev->bus->pm->prepare) + error = dev->bus->pm->prepare(dev); + suspend_report_result(dev->bus->pm->prepare, error); + if (error) + goto End; } if (dev->pwr_domain && dev->pwr_domain->ops.prepare) { diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 25edc9a3a48..54597c859ec 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -214,12 +214,12 @@ static int rpm_idle(struct device *dev, int rpmflags) dev->power.idle_notification = true; - if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle) - callback = dev->bus->pm->runtime_idle; - else if (dev->type && dev->type->pm && dev->type->pm->runtime_idle) + if (dev->type && dev->type->pm) callback = dev->type->pm->runtime_idle; else if (dev->class && dev->class->pm) callback = dev->class->pm->runtime_idle; + else if (dev->bus && dev->bus->pm) + callback = dev->bus->pm->runtime_idle; else callback = NULL; @@ -382,12 +382,12 @@ static int rpm_suspend(struct device *dev, int rpmflags) __update_runtime_status(dev, RPM_SUSPENDING); - if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend) - callback = dev->bus->pm->runtime_suspend; - else if (dev->type && dev->type->pm && dev->type->pm->runtime_suspend) + if (dev->type && dev->type->pm) callback = dev->type->pm->runtime_suspend; else if (dev->class && dev->class->pm) callback = dev->class->pm->runtime_suspend; + else if (dev->bus && dev->bus->pm) + callback = dev->bus->pm->runtime_suspend; else callback = NULL; @@ -584,12 +584,12 @@ static int rpm_resume(struct device *dev, int rpmflags) if (dev->pwr_domain) rpm_callback(dev->pwr_domain->ops.runtime_resume, dev); - if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume) - callback = dev->bus->pm->runtime_resume; - else if (dev->type && dev->type->pm && dev->type->pm->runtime_resume) + if (dev->type && dev->type->pm) callback = dev->type->pm->runtime_resume; else if (dev->class && dev->class->pm) callback = dev->class->pm->runtime_resume; + else if (dev->bus && dev->bus->pm) + callback = dev->bus->pm->runtime_resume; else callback = NULL; -- 2.39.5