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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-04-01 22:10:15 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-04-01 22:10:15 +0200
commit7b5c39389c86063e86fe8f2e0093c7197ddfa60a (patch)
tree550d98402980ee5a311b2990262404d2d49bed44 /Documentation/power
parentMerge branch 'pm-cpufreq' (diff)
parentPM / Runtime: Spelling s/competing/completing/ (diff)
downloadlinux-7b5c39389c86063e86fe8f2e0093c7197ddfa60a.tar.xz
linux-7b5c39389c86063e86fe8f2e0093c7197ddfa60a.zip
Merge branch 'pm-runtime'
* pm-runtime: PM / Runtime: Spelling s/competing/completing/ PM / Runtime: s/foo_process_requests/foo_process_next_request/ PM / Runtime: GENERIC_SUBSYS_PM_OPS is gone PM / Runtime: Correct documented return values for generic PM callbacks PM / Runtime: Split line longer than 80 characters PM / Runtime: dev_pm_info.runtime_error is signed
Diffstat (limited to 'Documentation/power')
-rw-r--r--Documentation/power/runtime_pm.txt29
1 files changed, 13 insertions, 16 deletions
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index b6ce00b2be9a..5f96daf8566a 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -232,7 +232,7 @@ defined in include/linux/pm.h:
equal to zero); the initial value of it is 1 (i.e. runtime PM is
initially disabled for all devices)
- unsigned int runtime_error;
+ int runtime_error;
- if set, there was a fatal error (one of the callbacks returned error code
as described in Section 2), so the helper funtions will not work until
this flag is cleared; this is the error code returned by the failing
@@ -401,11 +401,11 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
int pm_runtime_disable(struct device *dev);
- increment the device's 'power.disable_depth' field (if the value of that
field was previously zero, this prevents subsystem-level runtime PM
- callbacks from being run for the device), make sure that all of the pending
- runtime PM operations on the device are either completed or canceled;
- returns 1 if there was a resume request pending and it was necessary to
- execute the subsystem-level resume callback for the device to satisfy that
- request, otherwise 0 is returned
+ callbacks from being run for the device), make sure that all of the
+ pending runtime PM operations on the device are either completed or
+ canceled; returns 1 if there was a resume request pending and it was
+ necessary to execute the subsystem-level resume callback for the device
+ to satisfy that request, otherwise 0 is returned
int pm_runtime_barrier(struct device *dev);
- check if there's a resume request pending for the device and resume it
@@ -667,11 +667,11 @@ driver/base/power/generic_ops.c:
int pm_generic_runtime_suspend(struct device *dev);
- invoke the ->runtime_suspend() callback provided by the driver of this
- device and return its result, or return -EINVAL if not defined
+ device and return its result, or return 0 if not defined
int pm_generic_runtime_resume(struct device *dev);
- invoke the ->runtime_resume() callback provided by the driver of this
- device and return its result, or return -EINVAL if not defined
+ device and return its result, or return 0 if not defined
int pm_generic_suspend(struct device *dev);
- if the device has not been suspended at run time, invoke the ->suspend()
@@ -727,15 +727,12 @@ driver/base/power/generic_ops.c:
int pm_generic_restore_noirq(struct device *dev);
- invoke the ->restore_noirq() callback provided by the device's driver
-These functions can be assigned to the ->runtime_idle(), ->runtime_suspend(),
+These functions are the defaults used by the PM core, if a subsystem doesn't
+provide its own callbacks for ->runtime_idle(), ->runtime_suspend(),
->runtime_resume(), ->suspend(), ->suspend_noirq(), ->resume(),
->resume_noirq(), ->freeze(), ->freeze_noirq(), ->thaw(), ->thaw_noirq(),
-->poweroff(), ->poweroff_noirq(), ->restore(), ->restore_noirq() callback
-pointers in the subsystem-level dev_pm_ops structures.
-
-If a subsystem wishes to use all of them at the same time, it can simply assign
-the GENERIC_SUBSYS_PM_OPS macro, defined in include/linux/pm.h, to its
-dev_pm_ops structure pointer.
+->poweroff(), ->poweroff_noirq(), ->restore(), ->restore_noirq() in the
+subsystem-level dev_pm_ops structure.
Device drivers that wish to use the same function as a system suspend, freeze,
poweroff and runtime suspend callback, and similarly for system resume, thaw,
@@ -873,7 +870,7 @@ Here is a schematic pseudo-code example:
foo->is_suspended = 0;
pm_runtime_mark_last_busy(&foo->dev);
if (foo->num_pending_requests > 0)
- foo_process_requests(foo);
+ foo_process_next_request(foo);
unlock(&foo->private_lock);
return 0;
}