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author | Rafael J. Wysocki <rjw@sisk.pl> | 2011-12-26 02:42:20 +0400 |
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committer | Rafael J. Wysocki <rjw@sisk.pl> | 2011-12-26 02:42:20 +0400 |
commit | b7ba68c4a072c9aa8f04b8cf7838b6cd2f48d918 (patch) | |
tree | cd8f8029111fc52d06060691fb0325ba2e798e94 /Documentation/power/devices.txt | |
parent | 8d274ab7d3d6f23e2bc0e433c8d53acbe60a9773 (diff) | |
parent | 90363ddf0a1a4dccfbb8d0c10b8f488bc7fa69f8 (diff) | |
download | linux-b7ba68c4a072c9aa8f04b8cf7838b6cd2f48d918.tar.xz |
Merge branch 'pm-sleep' into pm-for-linus
* pm-sleep: (51 commits)
PM: Drop generic_subsys_pm_ops
PM / Sleep: Remove forward-only callbacks from AMBA bus type
PM / Sleep: Remove forward-only callbacks from platform bus type
PM: Run the driver callback directly if the subsystem one is not there
PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers
PM / Sleep: Merge internal functions in generic_ops.c
PM / Sleep: Simplify generic system suspend callbacks
PM / Hibernate: Remove deprecated hibernation snapshot ioctls
PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled()
PM / Sleep: Recommend [un]lock_system_sleep() over using pm_mutex directly
PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with [un]lock_system_sleep()
PM / Sleep: Make [un]lock_system_sleep() generic
PM / Sleep: Use the freezer_count() functions in [un]lock_system_sleep() APIs
PM / Freezer: Remove the "userspace only" constraint from freezer[_do_not]_count()
PM / Hibernate: Replace unintuitive 'if' condition in kernel/power/user.c with 'else'
Freezer / sunrpc / NFS: don't allow TASK_KILLABLE sleeps to block the freezer
PM / Sleep: Unify diagnostic messages from device suspend/resume
ACPI / PM: Do not save/restore NVS on Asus K54C/K54HR
PM / Hibernate: Remove deprecated hibernation test modes
PM / Hibernate: Thaw processes in SNAPSHOT_CREATE_IMAGE ioctl test path
...
Conflicts:
kernel/kmod.c
Diffstat (limited to 'Documentation/power/devices.txt')
-rw-r--r-- | Documentation/power/devices.txt | 37 |
1 files changed, 21 insertions, 16 deletions
diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index 3139fb505dce..20af7def23c8 100644 --- a/Documentation/power/devices.txt +++ b/Documentation/power/devices.txt @@ -126,7 +126,9 @@ The core methods to suspend and resume devices reside in struct dev_pm_ops pointed to by the ops member of struct dev_pm_domain, or by the pm member of struct bus_type, struct device_type and struct class. They are mostly of interest to the people writing infrastructure for platforms and buses, like PCI -or USB, or device type and device class drivers. +or USB, or device type and device class drivers. They also are relevant to the +writers of device drivers whose subsystems (PM domains, device types, device +classes and bus types) don't provide all power management methods. Bus drivers implement these methods as appropriate for the hardware and the drivers using it; PCI works differently from USB, and so on. Not many people @@ -268,32 +270,35 @@ 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 IRQF_NO_SUSPEND flag). -All phases use PM domain, bus, type, or class callbacks (that is, methods -defined in dev->pm_domain->ops, dev->bus->pm, dev->type->pm, or dev->class->pm). -These callbacks are regarded by the PM core as mutually exclusive. Moreover, -PM domain callbacks always take precedence over bus, type and class callbacks, -while type callbacks take precedence over bus and class callbacks, and class -callbacks take precedence over bus callbacks. To be precise, the following -rules are used to determine which callback to execute in the given phase: +All phases use PM domain, bus, type, class or driver callbacks (that is, methods +defined in dev->pm_domain->ops, dev->bus->pm, dev->type->pm, dev->class->pm or +dev->driver->pm). These callbacks are regarded by the PM core as mutually +exclusive. Moreover, PM domain callbacks always take precedence over all of the +other callbacks and, for example, type callbacks take precedence over bus, class +and driver callbacks. To be precise, the following rules are used to determine +which callback to execute in the given phase: - 1. If dev->pm_domain is present, the PM core will attempt to execute the - callback included in dev->pm_domain->ops. If that callback is not - present, no action will be carried out for the given device. + 1. If dev->pm_domain is present, the PM core will choose the callback + included in dev->pm_domain->ops for execution 2. Otherwise, if both dev->type and dev->type->pm are present, the callback - included in dev->type->pm will be executed. + included in dev->type->pm will be chosen for execution. 3. Otherwise, if both dev->class and dev->class->pm are present, the - callback included in dev->class->pm will be executed. + callback included in dev->class->pm will be chosen for execution. 4. Otherwise, if both dev->bus and dev->bus->pm are present, the callback - included in dev->bus->pm will be executed. + included in dev->bus->pm will be chosen for execution. This allows PM domains and device types to override callbacks provided by bus types or device 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. +The PM domain, type, class and bus callbacks may in turn invoke device- or +driver-specific methods stored in dev->driver->pm, but they don't have to do +that. + +If the subsystem callback chosen for execution is not present, the PM core will +execute the corresponding method from dev->driver->pm instead if there is one. Entering System Suspend |