diff mbox

[2/3,v2] acpi: thermal/sysfs-api.txt: document passive attribute for thermal zones

Message ID 200908221357.21567.elendil@planet.nl (mailing list archive)
State RFC, archived
Headers show

Commit Message

Frans Pop Aug. 22, 2009, 11:57 a.m. UTC
Signed-off-by: Frans Pop <elendil@planet.nl>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
---

While working on some further patches I discovered that polling_delay does
not actually determine the polling interval for a forced passive trip
point. Instead a hardcoded interval of 1 second is used (passive_delay).

I also saw that the thermal_sys driver is somewhat independent of ACPI,
so the third patch in the series may not be appropriate.

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diff mbox

Patch

diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index 48e9c5c..f6b3743 100644
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -3,7 +3,7 @@  Generic Thermal Sysfs driver How To
 
 Written by Sujith Thomas <sujith.thomas@intel.com>, Zhang Rui <rui.zhang@intel.com>
 
-Updated: 2 January 2008
+Updated: 21 August 2009
 
 Copyright (c)  2008 Intel Corporation
 
@@ -199,6 +199,15 @@  cdev[0-*]_trip_point
 	point.
 	RO, Optional
 
+passive
+	Attribute is only present for zones which do not have a passive
+	cooling policy (_PSV) defined in ACPI. Default is zero and can be
+	set to a temperature (in millidegrees) to enable a passive trip
+	point for the zone. Activation is done by polling with an interval
+	of 1 second.
+	Unit: millidegrees Celsius
+	RW, Optional
+
 *****************************
 * Cooling device attributes *
 *****************************
@@ -230,8 +239,9 @@  thermal_zone_device (thermal_zone1) with 4 trip points in all.
 It has one processor and one fan, which are both registered as
 thermal_cooling_device.
 
-If the processor is listed in _PSL method, and the fan is listed in _AL0
-method, the sys I/F structure will be built like this:
+If the processor is listed in _PSL method, the fan is listed in _AL0
+method, and the zone has a _PSV method, the sys I/F structure will be
+built like this:
 
 /sys/class/thermal: