linux-stable.git/drivers/thermal/step_wise.c, branch linux-3.16.y

thermal: step_wise: fix: Prevent from binary overflow when trend is dropping

2015-08-10T08:54:04+00:00

commit 26bb0e9a1a938ec98ee07aa76533f1a711fba706 upstream.

It turns out that some boards can have instance->lower greater than 0 and
when thermal trend is dropping it results with next_target equal to -1.

Since the next_target is defined as unsigned long it is interpreted as
0xFFFFFFFF and larger than instance->upper.
As a result the next_target is set to instance->upper which ramps up to
maximal cooling device target when the temperature is steadily decreasing.

Signed-off-by: Lukasz Majewski 
Signed-off-by: Zhang Rui 
Cc: Mason 
Signed-off-by: Luis Henriques

thermal: step_wise: Revert optimization

2015-06-12T11:55:03+00:00

Commit 178c2490b99f898efc06d1ad75cadc84f13021a6 ("thermal: step_wise:
cdev only needs update on a new target state") broke driver acerhdf.
That driver abused the step_wise thermal governor until the bang_bang
governor was available, and the optimization broke this usage model.

Kernels v3.12 to v3.18 are affected. In v3.19 the acerhdf driver was
switched to the bang_bang governor and that solved the problem.

For kernels v3.12 to v3.17, the bang_bang governor isn't available
yet so the easiest fix is to revert the optimization.

Signed-off-by: Jean Delvare 
Reported-by: Dieter Jurzitza (https://bugzilla.opensuse.org/show_bug.cgi?id=925961)
Tested-by: Peter Feuerer 
Tested-by: Dieter Jurzitza
Signed-off-by: Luis Henriques

thermal: debug: add debug statement for core and step_wise

2014-01-02T02:52:48+00:00

To ease debugging thermal problem, add these dynamic debug statements
so that user do not need rebuild kernel to see these info.

Based on a patch from Zhang Rui for debugging on bugzilla:
https://bugzilla.kernel.org/attachment.cgi?id=98671

A sample output after we turn on dynamic debug with the following cmd:
# echo 'module thermal_sys +fp' > /sys/kernel/debug/dynamic_debug/control
is like:

[  355.147627] update_temperature: thermal thermal_zone0: last_temperature=52000, current_temperature=55000
[  355.147636] thermal_zone_trip_update: thermal thermal_zone0: Trip1[type=1,temp=79000]:trend=2,throttle=0
[  355.147644] get_target_state: thermal cooling_device8: cur_state=0
[  355.147647] thermal_zone_trip_update: thermal cooling_device8: old_target=-1, target=-1
[  355.147652] get_target_state: thermal cooling_device7: cur_state=0
[  355.147655] thermal_zone_trip_update: thermal cooling_device7: old_target=-1, target=-1
[  355.147660] get_target_state: thermal cooling_device6: cur_state=0
[  355.147663] thermal_zone_trip_update: thermal cooling_device6: old_target=-1, target=-1
[  355.147668] get_target_state: thermal cooling_device5: cur_state=0
[  355.147671] thermal_zone_trip_update: thermal cooling_device5: old_target=-1, target=-1
[  355.147678] thermal_zone_trip_update: thermal thermal_zone0: Trip2[type=0,temp=90000]:trend=1,throttle=0
[  355.147776] get_target_state: thermal cooling_device0: cur_state=0
[  355.147783] thermal_zone_trip_update: thermal cooling_device0: old_target=-1, target=-1
[  355.147792] thermal_zone_trip_update: thermal thermal_zone0: Trip3[type=0,temp=80000]:trend=1,throttle=0
[  355.147845] get_target_state: thermal cooling_device1: cur_state=0
[  355.147849] thermal_zone_trip_update: thermal cooling_device1: old_target=-1, target=-1
[  355.147856] thermal_zone_trip_update: thermal thermal_zone0: Trip4[type=0,temp=70000]:trend=1,throttle=0
[  355.147904] get_target_state: thermal cooling_device2: cur_state=0
[  355.147908] thermal_zone_trip_update: thermal cooling_device2: old_target=-1, target=-1
[  355.147915] thermal_zone_trip_update: thermal thermal_zone0: Trip5[type=0,temp=60000]:trend=1,throttle=0
[  355.147963] get_target_state: thermal cooling_device3: cur_state=0
[  355.147967] thermal_zone_trip_update: thermal cooling_device3: old_target=-1, target=-1
[  355.147973] thermal_zone_trip_update: thermal thermal_zone0: Trip6[type=0,temp=55000]:trend=1,throttle=1
[  355.148022] get_target_state: thermal cooling_device4: cur_state=0
[  355.148025] thermal_zone_trip_update: thermal cooling_device4: old_target=-1, target=1
[  355.148036] thermal_cdev_update: thermal cooling_device4: zone0->target=1
[  355.169279] thermal_cdev_update: thermal cooling_device4: set to state 1

Signed-off-by: Aaron Lu 
Acked-by: Eduardo Valentin 
Signed-off-by: Zhang Rui

thermal: step_wise: return instance->target by default

2013-08-15T07:49:20+00:00

In case the trend is not changing or when there is no
request for throttling, it is expected that the instance
would not change its requested target. This patch improves
the code implementation to cover for this expected behavior.

With current implementation, the instance will always
reset to cdev.cur_state, even in not expected cases,
like those mentioned above.

This patch changes the step_wise governor implementation
of get_target so that we accomplish:
(a) - default value will be current instance->target, so
we do not change the thermal instance target unnecessarily.
(b) - the code now it is clear about what is the intention.
There is a clear statement of what are the expected outcomes
(c) - removal of hardcoded constants, now it is put in use
the THERMAL_NO_TARGET macro.
(d) - variable names are also improved so that reader can
clearly understand the difference between instance cur target,
next target and cdev cur_state.

Cc: Zhang Rui 
Cc: Durgadoss R 
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reported-by: Ruslan Ruslichenko 
Signed-of-by: Eduardo Valentin 
Signed-off-by: Zhang Rui

thermal: step_wise: cdev only needs update on a new target state

2013-08-15T07:48:59+00:00

The cooling device only needs update on a new target state.  Since we
already check old target in thermal_zone_trip_update(), we can do one
more check to see if it's a new target state.  If not, we can reasonably
save some uncecesary code execution.

Signed-off-by: Shawn Guo 
Acked-by: Eduardo Valentin 
Signed-off-by: Zhang Rui

Thermal: build thermal governors into thermal_sys module

2013-04-14T15:28:43+00:00

The thermal governors are part of the thermal framework,
rather than a seperate feature/module.
Because the generic thermal layer can not work without
thermal governors, and it must load the thermal governors
during its initialization.

Build them into one module in this patch.

This also fix a problem that the generic thermal layer does not
work when CONFIG_THERMAL=m and CONFIG_THERMAL_GOV_XXX=y.

Signed-off-by: Zhang Rui 
Acked-by: Eduardo Valentin 
Acked-by: Durgadoss R

thermal: step_wise: set throttle target within thermal instance limits

2013-04-11T23:23:50+00:00

When selecting a target cooling state in get_target_state(), make sure
that the state is at least as high as the minimum when the temperature
is rising and at least as low as the maximum when the temperature is
falling.  This is necessary because, in the THREAML_TREND_RAISING and
THERMAL_TREND_DROPPING cases, the current state may only be incremented
or decremented by one even if it is outside the bounds of the thermal
instance.  This might occur, for example, if the CPU is heating up
and hits a thermal trip point for the first time when it's frequency
is much higher than the range specified by the thermal instance
corresponding to the trip point.

Signed-off-by: Andrew Bresticker 
Acked-by: Eduardo Valentin 
Signed-off-by: Zhang Rui

step_wise: Unify the code for both throttle and dethrottle

2013-01-04T07:22:37+00:00

Signed-off-by: Zhang Rui

Introduce THERMAL_TREND_RAISE/DROP_FULL support for step_wise governor

2013-01-04T07:22:37+00:00

step_wise governor should set the device cooling state to
upper/lower limit directly when THERMAL_TREND_RAISE/DROP_FULL.

Signed-off-by: Zhang Rui

Thermal: Fix DEFAULT_THERMAL_GOVERNOR

2012-12-12T07:34:48+00:00

Fix DEFAULT_THERMAL_GOVERNOR to be consistant with the
default governor selected in kernel config file.

Signed-off-by: Zhang Rui