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| author | Lukasz Majewski <l.majewski@samsung.com> | 2014-09-24 10:27:10 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-08-03 09:29:52 -0700 |
| commit | 87fe76cf55e7bd5be13ba50094fdac0b6547b65d (patch) | |
| tree | 4a1edb05ac8f1b350f5320969339e2c0a03e0a94 /drivers | |
| parent | 9b35e24e866fd5456fec99277a80c4d7622941f1 (diff) | |
| download | lwn-87fe76cf55e7bd5be13ba50094fdac0b6547b65d.tar.gz lwn-87fe76cf55e7bd5be13ba50094fdac0b6547b65d.zip | |
thermal: step_wise: fix: Prevent from binary overflow when trend is dropping
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 <l.majewski@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Cc: Mason <slash.tmp@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/thermal/step_wise.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/thermal/step_wise.c b/drivers/thermal/step_wise.c index ee52ab7d3730..c501eba601da 100644 --- a/drivers/thermal/step_wise.c +++ b/drivers/thermal/step_wise.c @@ -76,7 +76,7 @@ static unsigned long get_target_state(struct thermal_instance *instance, next_target = instance->upper; break; case THERMAL_TREND_DROPPING: - if (cur_state == instance->lower) { + if (cur_state <= instance->lower) { if (!throttle) next_target = THERMAL_NO_TARGET; } else { |