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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-02-11 00:35:23 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-02-11 00:35:23 +0100
commitb02f6695f7601c4f8442b9cf4636802e7fa8d550 (patch)
tree6a4735abce3fc9a27e029f15a051d07fda92f190 /Documentation/power
parentb28a960c42fcd9cfc987441fa6d1c1a471f0f9ed (diff)
downloadlinux-linaro-stable-b02f6695f7601c4f8442b9cf4636802e7fa8d550.tar.gz
PM / QoS: Rename device resume latency QoS items
Rename symbols, variables, functions and structure fields related do the resume latency device PM QoS type so that it is clear where they belong (in particular, to avoid confusion with the latency tolerance device PM QoS type introduced by a subsequent changeset). Update the PM QoS documentation to better reflect its current state. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'Documentation/power')
-rw-r--r--Documentation/power/pm_qos_interface.txt37
1 files changed, 16 insertions, 21 deletions
diff --git a/Documentation/power/pm_qos_interface.txt b/Documentation/power/pm_qos_interface.txt
index 483632087788..22cb8f51182a 100644
--- a/Documentation/power/pm_qos_interface.txt
+++ b/Documentation/power/pm_qos_interface.txt
@@ -89,16 +89,16 @@ node.
2. PM QoS per-device latency and flags framework
For each device, there are two lists of PM QoS requests. One is maintained
-along with the aggregated target of latency value and the other is for PM QoS
-flags. Values are updated in response to changes of the request list.
+along with the aggregated target of resume latency value and the other is for
+PM QoS flags. Values are updated in response to changes of the request list.
-Target latency value is simply the minimum of the request values held in the
-parameter list elements. The PM QoS flags aggregate value is a gather (bitwise
-OR) of all list elements' values. Two device PM QoS flags are defined currently:
-PM_QOS_FLAG_NO_POWER_OFF and PM_QOS_FLAG_REMOTE_WAKEUP.
+Target resume latency value is simply the minimum of the request values held in
+the parameter list elements. The PM QoS flags aggregate value is a gather
+(bitwise OR) of all list elements' values. Two device PM QoS flags are defined
+currently: PM_QOS_FLAG_NO_POWER_OFF and PM_QOS_FLAG_REMOTE_WAKEUP.
-Note: the aggregated target value is implemented as an atomic variable so that
-reading the aggregated value does not require any locking mechanism.
+Note: the aggregated target value is implemented in such a way that reading the
+aggregated value does not require any locking mechanism.
From kernel mode the use of this interface is the following:
@@ -137,14 +137,14 @@ Add a PM QoS request for the first direct ancestor of the given device whose
power.ignore_children flag is unset.
int dev_pm_qos_expose_latency_limit(device, value)
-Add a request to the device's PM QoS list of latency constraints and create
-a sysfs attribute pm_qos_resume_latency_us under the device's power directory
-allowing user space to manipulate that request.
+Add a request to the device's PM QoS list of resume latency constraints and
+create a sysfs attribute pm_qos_resume_latency_us under the device's power
+directory allowing user space to manipulate that request.
void dev_pm_qos_hide_latency_limit(device)
Drop the request added by dev_pm_qos_expose_latency_limit() from the device's
-PM QoS list of latency constraints and remove sysfs attribute pm_qos_resume_latency_us
-from the device's power directory.
+PM QoS list of resume latency constraints and remove sysfs attribute
+pm_qos_resume_latency_us from the device's power directory.
int dev_pm_qos_expose_flags(device, value)
Add a request to the device's PM QoS list of flags and create sysfs attributes
@@ -163,7 +163,7 @@ a per-device notification tree and a global notification tree.
int dev_pm_qos_add_notifier(device, notifier):
Adds a notification callback function for the device.
The callback is called when the aggregated value of the device constraints list
-is changed.
+is changed (for resume latency device PM QoS only).
int dev_pm_qos_remove_notifier(device, notifier):
Removes the notification callback function for the device.
@@ -171,14 +171,9 @@ Removes the notification callback function for the device.
int dev_pm_qos_add_global_notifier(notifier):
Adds a notification callback function in the global notification tree of the
framework.
-The callback is called when the aggregated value for any device is changed.
+The callback is called when the aggregated value for any device is changed
+(for resume latency device PM QoS only).
int dev_pm_qos_remove_global_notifier(notifier):
Removes the notification callback function from the global notification tree
of the framework.
-
-
-From user mode:
-No API for user space access to the per-device latency constraints is provided
-yet - still under discussion.
-