Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754371AbbHLJk0 (ORCPT ); Wed, 12 Aug 2015 05:40:26 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:60435 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934025AbbHLI5W (ORCPT ); Wed, 12 Aug 2015 04:57:22 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Lukasz Majewski , Zhang Rui , Mason , Luis Henriques Subject: [PATCH 3.16.y-ckt 016/118] thermal: step_wise: fix: Prevent from binary overflow when trend is dropping Date: Wed, 12 Aug 2015 09:55:18 +0100 Message-Id: <1439369820-27005-17-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1439369820-27005-1-git-send-email-luis.henriques@canonical.com> References: <1439369820-27005-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1644 Lines: 42 3.16.7-ckt16 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Lukasz Majewski 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 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 { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/