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SubjectRe: [PATCH 1/4] thermal: Add new thermal trend type to support quick cooling
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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.

I can write such a governor if you do not have time to.

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 <amit.daniel@samsung.com>
> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@linaro.org>
> ---
> 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 */




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