From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lukasz Majewski Subject: [PATCH 1/3] thermal: step_wise: fix: Prevent from binary overflow when trend is dropping Date: Wed, 24 Sep 2014 10:27:10 +0200 Message-ID: <1411547232-21493-2-git-send-email-l.majewski@samsung.com> References: <1411547232-21493-1-git-send-email-l.majewski@samsung.com> Return-path: In-reply-to: <1411547232-21493-1-git-send-email-l.majewski@samsung.com> Sender: linux-kernel-owner@vger.kernel.org To: Zhang Rui , Eduardo Valentin Cc: Linux PM list , Lukasz Majewski , Bartlomiej Zolnierkiewicz , linux-kernel@vger.kernel.org, Lukasz Majewski List-Id: linux-pm@vger.kernel.org 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 --- 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 3b54c2c..fdd1f52 100644 --- a/drivers/thermal/step_wise.c +++ b/drivers/thermal/step_wise.c @@ -77,7 +77,7 @@ 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 { -- 2.0.0.rc2