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SubjectRe: [PATCH 1/4] thermal: Add new thermal trend type to support quick cooling
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On 8 November 2012 11:31, Zhang Rui <rui.zhang@intel.com> 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 <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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