From 072cb4b109eb85c32fcf0f8073fe280fec777f7c Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Wed, 24 Sep 2014 10:27:10 +0200 Subject: [PATCH] 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 Signed-off-by: Zhang Rui Cc: Mason Signed-off-by: Luis Henriques --- drivers/thermal/step_wise.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/thermal/step_wise.c b/drivers/thermal/step_wise.c index ee52ab7d37301..c501eba601da9 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 { -- 2.47.3