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authorFrans Pop <elendil@planet.nl>2009-10-26 08:39:02 +0100
committerLen Brown <len.brown@intel.com>2009-11-05 18:18:10 -0500
commit3d8e3ad879441ae14c5957b933028daf39d252b0 (patch)
tree33f81135d8a8518e2507bc1db51b4adf29d60e41 /Documentation/thermal
parent7fb2616e249184e217f9818a7662596165710ea4 (diff)
downloadlwn-3d8e3ad879441ae14c5957b933028daf39d252b0.tar.gz
lwn-3d8e3ad879441ae14c5957b933028daf39d252b0.zip
thermal: add sanity check for the passive attribute
Values below 1000 milli-celsius don't make sense and can cause the system to go into a thermal heart attack: the actual temperature will always be lower and thus the system will be throttled down to its lowest setting. An additional problem is that values below 1000 will show as 0 in /proc/acpi/thermal/TZx/trip_points:passive. cat passive 0 echo -n 90 >passive bash: echo: write error: Invalid argument echo -n 90000 >passive cat passive 90000 Signed-off-by: Frans Pop <elendil@planet.nl> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'Documentation/thermal')
-rw-r--r--Documentation/thermal/sysfs-api.txt1
1 files changed, 1 insertions, 0 deletions
diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index a87dc277a5ca..cb3d15bc1aeb 100644
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -206,6 +206,7 @@ passive
passive trip point for the zone. Activation is done by polling with
an interval of 1 second.
Unit: millidegrees Celsius
+ Valid values: 0 (disabled) or greater than 1000
RW, Optional
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