From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754559Ab2KHG01 (ORCPT ); Thu, 8 Nov 2012 01:26:27 -0500 Received: from mail-oa0-f46.google.com ([209.85.219.46]:43239 "EHLO mail-oa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752304Ab2KHG00 (ORCPT ); Thu, 8 Nov 2012 01:26:26 -0500 MIME-Version: 1.0 In-Reply-To: <1352354503.2190.7.camel@rzhang1-mobl4> References: <1352348786-24255-1-git-send-email-amit.kachhap@linaro.org> <1352348786-24255-2-git-send-email-amit.kachhap@linaro.org> <1352354503.2190.7.camel@rzhang1-mobl4> Date: Thu, 8 Nov 2012 11:56:25 +0530 Message-ID: Subject: Re: [PATCH 1/4] thermal: Add new thermal trend type to support quick cooling From: Amit Kachhap To: Zhang Rui Cc: linux-pm@lists.linux-foundation.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, durgadoss.r@intel.com, lenb@kernel.org, linux-acpi@vger.kernel.org, jonghwa3.lee@samsung.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8 November 2012 11:31, Zhang Rui wrote: > On Thu, 2012-11-08 at 09:56 +0530, Amit Daniel Kachhap wrote: >> This modification adds 2 new thermal trend type THERMAL_TREND_RAISE_FULL >> and THERMAL_TREND_DROP_FULL. This thermal trend can be used to quickly >> jump to the upper or lower cooling level instead of incremental increase >> or decrease. > > IMO, what we need is a new more aggressive cooling governor which always > uses upper limit when the temperature is raising and lower limit when > the temperature is dropping. Yes I agree that a new aggressive governor is the best approach but then i thought adding a new trend type is a simple solution to achieve this and since most of the governor logic might be same as the step-wise governor. I have no objection in doing it through governor. > > I can write such a governor if you do not have time to. ok. thanks > > thanks, > rui >> This is needed for temperature sensors which support rising/falling >> threshold interrupts and polling can be totally avoided. >> > > >> Signed-off-by: Amit Daniel Kachhap >> Signed-off-by: Amit Daniel Kachhap >> --- >> drivers/thermal/step_wise.c | 19 +++++++++++++++---- >> include/linux/thermal.h | 2 ++ >> 2 files changed, 17 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/thermal/step_wise.c b/drivers/thermal/step_wise.c >> index 1242cff..0d2d8d6 100644 >> --- a/drivers/thermal/step_wise.c >> +++ b/drivers/thermal/step_wise.c >> @@ -35,6 +35,10 @@ >> * state for this trip point >> * b. if the trend is THERMAL_TREND_DROPPING, use lower cooling >> * state for this trip point >> + * c. if the trend is THERMAL_TREND_RAISE_FULL, use highest cooling >> + * state for this trip point >> + * d. if the trend is THERMAL_TREND_DROP_FULL, use lowest cooling >> + * state for this trip point >> */ >> static unsigned long get_target_state(struct thermal_instance *instance, >> enum thermal_trend trend) >> @@ -50,7 +54,10 @@ static unsigned long get_target_state(struct thermal_instance *instance, >> } else if (trend == THERMAL_TREND_DROPPING) { >> cur_state = cur_state > instance->lower ? >> (cur_state - 1) : instance->lower; >> - } >> + } else if (trend == THERMAL_TREND_RAISE_FULL) >> + cur_state = instance->upper; >> + else if (trend == THERMAL_TREND_DROP_FULL) >> + cur_state = instance->lower; >> >> return cur_state; >> } >> @@ -87,7 +94,8 @@ static void update_instance_for_throttle(struct thermal_zone_device *tz, >> } >> >> static void update_instance_for_dethrottle(struct thermal_zone_device *tz, >> - int trip, enum thermal_trip_type trip_type) >> + int trip, enum thermal_trip_type trip_type, >> + enum thermal_trend trend) >> { >> struct thermal_instance *instance; >> struct thermal_cooling_device *cdev; >> @@ -101,7 +109,10 @@ static void update_instance_for_dethrottle(struct thermal_zone_device *tz, >> cdev = instance->cdev; >> cdev->ops->get_cur_state(cdev, &cur_state); >> >> - instance->target = cur_state > instance->lower ? >> + if (trend == THERMAL_TREND_DROP_FULL) >> + instance->target = instance->lower; >> + else >> + instance->target = cur_state > instance->lower ? >> (cur_state - 1) : THERMAL_NO_TARGET; >> >> /* Deactivate a passive thermal instance */ >> @@ -133,7 +144,7 @@ static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip) >> if (tz->temperature >= trip_temp) >> update_instance_for_throttle(tz, trip, trip_type, trend); >> else >> - update_instance_for_dethrottle(tz, trip, trip_type); >> + update_instance_for_dethrottle(tz, trip, trip_type, trend); >> >> mutex_unlock(&tz->lock); >> } >> diff --git a/include/linux/thermal.h b/include/linux/thermal.h >> index 807f214..8bce3ec 100644 >> --- a/include/linux/thermal.h >> +++ b/include/linux/thermal.h >> @@ -68,6 +68,8 @@ enum thermal_trend { >> THERMAL_TREND_STABLE, /* temperature is stable */ >> THERMAL_TREND_RAISING, /* temperature is raising */ >> THERMAL_TREND_DROPPING, /* temperature is dropping */ >> + THERMAL_TREND_RAISE_FULL, /* Apply highest cooling action*/ >> + THERMAL_TREND_DROP_FULL, /* Apply lowest cooling action*/ >> }; >> >> /* Events supported by Thermal Netlink */ > >