Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (32 commits)
  ACPI: thermal: show temperature in millidegree Celsius
  thermal: fix generic thermal I/F for hwmon
  acer-wmi: build depends on i8042
  documentation:  Move power-related files to Documentation/power/
  ACPI: buffer array too short in drivers/acpi/system.c
  acer-wmi: Add DMI quirk for mail LED support on Acer Aspire 3610/ 5610
  acer-wmi: Fix DSDT path in documentation
  acer-wmi: Make device detection error messages more descriptive
  laptops: move laptop-mode.txt to Documentation/laptops/
  ACPICA: Warn if packages with invalid references are evaluated
  ACPI: add _PRT quirks to work around broken firmware
  Hibernation: Fix mark_nosave_pages()
  ACPI: Ignore _BQC object when registering backlight device
  ACPI: WMI: Clean up handling of spec violating data blocks
  acer-wmi: Don't warn if mail LED cannot be detected
  acer-wmi: Rename mail LED correctly & remove hardcoded colour
  ACPI: use ACPI_DEBUG_PRINT instead of printk in acpi_processor_hotplug_notify()
  ACPI: button: make real parent for input devices in device tree
  toshiba_acpi: Enable autoloading
  ACPI: EC: Handle IRQ storm on Acer laptops
  ...

1 files changed, 59 insertions, 0 deletions

diff --git a/Documentation/power/pm_qos_interface.txt b/Documentation/power/pm_qos_interface.txt
new file mode 100644
index 00000000000..49adb1a3351
--- /dev/null
+++ b/Documentation/power/pm_qos_interface.txt
@@ -0,0 +1,59 @@
+PM quality of Service interface.
+
+This interface provides a kernel and user mode interface for registering
+performance expectations by drivers, subsystems and user space applications on
+one of the parameters.
+
+Currently we have {cpu_dma_latency, network_latency, network_throughput} as the
+initial set of pm_qos parameters.
+
+The infrastructure exposes multiple misc device nodes one per implemented
+parameter.  The set of parameters implement is defined by pm_qos_power_init()
+and pm_qos_params.h.  This is done because having the available parameters
+being runtime configurable or changeable from a driver was seen as too easy to
+abuse.
+
+For each parameter a list of performance requirements is maintained along with
+an aggregated target value.  The aggregated target value is updated with
+changes to the requirement list or elements of the list.  Typically the
+aggregated target value is simply the max or min of the requirement values held
+in the parameter list elements.
+
+From kernel mode the use of this interface is simple:
+pm_qos_add_requirement(param_id, name, target_value):
+Will insert a named element in the list for that identified PM_QOS parameter
+with the target value.  Upon change to this list the new target is recomputed
+and any registered notifiers are called only if the target value is now
+different.
+
+pm_qos_update_requirement(param_id, name, new_target_value):
+Will search the list identified by the param_id for the named list element and
+then update its target value, calling the notification tree if the aggregated
+target is changed.  with that name is already registered.
+
+pm_qos_remove_requirement(param_id, name):
+Will search the identified list for the named element and remove it, after
+removal it will update the aggregate target and call the notification tree if
+the target was changed as a result of removing the named requirement.
+
+
+From user mode:
+Only processes can register a pm_qos requirement.  To provide for automatic
+cleanup for process the interface requires the process to register its
+parameter requirements in the following way:
+
+To register the default pm_qos target for the specific parameter, the process
+must open one of /dev/[cpu_dma_latency, network_latency, network_throughput]
+
+As long as the device node is held open that process has a registered
+requirement on the parameter.  The name of the requirement is "process_<PID>"
+derived from the current->pid from within the open system call.
+
+To change the requested target value the process needs to write a s32 value to
+the open device node.  This translates to a pm_qos_update_requirement call.
+
+To remove the user mode request for a target value simply close the device
+node.
+
+
+