From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Lam Subject: [PATCH 1/1] thermal: Check cooling device's current state before declaring it inactive Date: Sun, 30 Dec 2012 13:57:36 -0500 Message-ID: <1356893856-26249-1-git-send-email-lambchop468@gmail.com> Return-path: Received: from mail-vb0-f47.google.com ([209.85.212.47]:36522 "EHLO mail-vb0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754787Ab2L3TDY (ORCPT ); Sun, 30 Dec 2012 14:03:24 -0500 Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Zhang Rui , Durgadoss R Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Alexander Lam It is possible for a cooling device to become active in between calls to the thermal governor. An example of this is the acerhdf driver, which can hand control of the cooling device over to the system firmware. Upon returning control back to the thermal system, the cooling device might be running again, so checking the current state of the cooling device is required. Signed-off-by: Alexander Lam --- drivers/thermal/step_wise.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/thermal/step_wise.c b/drivers/thermal/step_wise.c index 0cd5e9f..0eeb709 100644 --- a/drivers/thermal/step_wise.c +++ b/drivers/thermal/step_wise.c @@ -94,16 +94,21 @@ static void update_instance_for_dethrottle(struct thermal_zone_device *tz, unsigned long cur_state; list_for_each_entry(instance, &tz->thermal_instances, tz_node) { - if (instance->trip != trip || - instance->target == THERMAL_NO_TARGET) + if (instance->trip != trip) continue; cdev = instance->cdev; cdev->ops->get_cur_state(cdev, &cur_state); - instance->target = cur_state > instance->lower ? + cur_state = cur_state > instance->lower ? (cur_state - 1) : THERMAL_NO_TARGET; + if (cur_state == THERMAL_NO_TARGET && + instance->target == THERMAL_NO_TARGET) + continue; + + instance->target = cur_state; + /* Deactivate a passive thermal instance */ if (instance->target == THERMAL_NO_TARGET) update_passive_instance(tz, trip_type, -1); -- 1.8.0.2