This is a note to let you know that I've just added the patch titled
ACPI / thermal: do not always return THERMAL_TREND_RAISING for active trip points
to the 3.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
acpi-thermal-do-not-always-return-thermal_trend_raising-for-active-trip-points.patch
and it can be found in the queue-3.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 94a409319561ec1847fd9bf996a2d5843ad00932 Mon Sep 17 00:00:00 2001
From: Zhang Rui <rui.zhang@xxxxxxxxx>
Date: Fri, 26 Apr 2013 09:19:53 +0000
Subject: ACPI / thermal: do not always return THERMAL_TREND_RAISING for active trip points
From: Zhang Rui <rui.zhang@xxxxxxxxx>
commit 94a409319561ec1847fd9bf996a2d5843ad00932 upstream.
Commit 4ae46be "Thermal: Introduce thermal_zone_trip_update()"
introduced a regression causing the fan to be always on even when
the system is idle.
My original idea in that commit is that:
- when the current temperature is above the trip point,
keep the fan on, even if the temperature is dropping.
- when the current temperature is below the trip point,
turn on the fan when the temperature is raising,
turn off the fan when the temperature is dropping.
But this is what the code actually does:
- when the current temperature is above the trip point,
the fan keeps on.
- when the current temperature is below the trip point,
the fan is always on because thermal_get_trend()
in driver/acpi/thermal.c returns THERMAL_TREND_RAISING.
Thus the fan keeps running even if the system is idle.
Fix this in drivers/acpi/thermal.c.
[rjw: Changelog]
References: https://bugzilla.kernel.org/show_bug.cgi?id=56591
References: https://bugzilla.kernel.org/show_bug.cgi?id=56601
References: https://bugzilla.kernel.org/show_bug.cgi?id=50041#c45
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
Tested-by: Matthias <morpheusxyz123@xxxxxxxx>
Tested-by: Ville Syrjälä <syrjala@xxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/acpi/thermal.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -719,9 +719,19 @@ static int thermal_get_trend(struct ther
return -EINVAL;
if (type == THERMAL_TRIP_ACTIVE) {
- /* aggressive active cooling */
- *trend = THERMAL_TREND_RAISING;
- return 0;
+ unsigned long trip_temp;
+ unsigned long temp = KELVIN_TO_MILLICELSIUS(tz->temperature,
+ tz->kelvin_offset);
+ if (thermal_get_trip_temp(thermal, trip, &trip_temp))
+ return -EINVAL;
+
+ if (temp > trip_temp) {
+ *trend = THERMAL_TREND_RAISING;
+ return 0;
+ } else {
+ /* Fall back on default trend */
+ return -EINVAL;
+ }
}
/*
Patches currently in stable-queue which might be from rui.zhang@xxxxxxxxx are
queue-3.8/acpi-thermal-do-not-always-return-thermal_trend_raising-for-active-trip-points.patch
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