kernel.git/drivers/thermal/gov_power_allocator.c, branch linux-5.19.y

thermal/core/power allocator: Use the lockless __thermal_cdev_update() function

2021-04-22T21:51:32Z

Use the new helper function and avoid unnecessery second lock/unlock, which was present in old approach with thermal_cdev_update(). Signed-off-by: Lukasz Luba Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20210422153624.6074-4-lukasz.luba@arm.com

thermal/core/power_allocator: Update once cooling devices when temp is low

2021-04-22T21:51:14Z

The cooling device state change generates an event, also when there is no need, because temperature is low and device is not throttled. Avoid to unnecessary update the cooling device which means also not sending event. The cooling device state has not changed because the temperature is still below the first activation trip point value, so we can do this. Add a tracking mechanism to make sure it updates cooling devices only once - when the temperature dropps below first trip point. Reported-by: Daniel Lezcano Signed-off-by: Lukasz Luba Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20210422114308.29684-4-lukasz.luba@arm.com

thermal/core/power_allocator: Maintain the device statistics from going stale

2021-04-22T21:50:49Z

When the temperature is below the first activation trip point the cooling devices are not checked, so they cannot maintain fresh statistics. It leads into the situation, when temperature crosses first trip point, the statistics are stale and show state for very long period. This has impact on IPA algorithm calculation and wrong decisions. Thus, check the cooling devices even when the temperature is low, to refresh these statistics. Signed-off-by: Lukasz Luba Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20210422114308.29684-3-lukasz.luba@arm.com

thermal/core/power_allocator: Using round the division when re-divvying up power

2021-03-16T11:44:20Z

The division is used directly in re-divvying up power, the decimal part will be discarded, devices will get less than the extra_actor_power - 1. if using round the division to make the calculation more accurate. For example: actor0 received more than its max_power, it has the extra_power 759 actor1 received less than its max_power, it require extra_actor_power 395 actor2 received less than its max_power, it require extra_actor_power 365 actor1 and actor2 require the total capped_extra_power 760 using division in re-divvying up power actor1 would actually get the extra_actor_power 394 actor2 would actually get the extra_actor_power 364 if using round the division in re-divvying up power actor1 would actually get the extra_actor_power 394 actor2 would actually get the extra_actor_power 365 Signed-off-by: Jeson Gao Reviewed-by: Lukasz Luba Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/1615796737-4688-1-git-send-email-gao.yunxiao6@gmail.com

thermal: power allocator: fail binding for non-power actor devices

2021-01-19T21:31:10Z

The thermal zone can have cooling devices which are missing power actor API. This could be due to missing Energy Model for devfreq or cpufreq cooling device. In this case it is safe to fail the binding rather than trying to workaround and control the temperature in such thermal zone. Signed-off-by: Lukasz Luba Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20210119114126.19480-1-lukasz.luba@arm.com

thermal/core: Remove ms based delay fields

2021-01-19T21:23:49Z

The code does no longer use the ms unit based fields to set the delays as they are replaced by the jiffies. Remove them and replace their user to use the jiffies version instead. Cc: Thara Gopinath Signed-off-by: Daniel Lezcano Reviewed-by: Lukasz Luba Reviewed-by: Peter Kästle Acked-by: Hans de Goede Link: https://lore.kernel.org/r/20201216220337.839878-3-daniel.lezcano@linaro.org

thermal: power allocator: change the 'k_*' always in estimate_pid_constants()

2020-11-26T16:11:59Z

The PID coefficients should be estimated again when there was a change to sustainable power value made by user. This change removes unused argument 'force' and makes the function ready for such updates. Signed-off-by: Lukasz Luba Reviewed-by: Ionela Voinescu Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20201124161025.27694-4-lukasz.luba@arm.com

thermal: power allocator: refactor sustainable power estimation

2020-11-26T16:11:59Z

The sustainable power value might come from the Device Tree or can be estimated in run time. The sustainable power might be updated by the user via sysfs interface, which should trigger new estimation of PID coefficients. There is no need to estimate it every time when the governor is called and temperature is high. Instead, store the estimated value and make it available via standard sysfs interface, so it can be checked from the user-space. Signed-off-by: Lukasz Luba Reviewed-by: Ionela Voinescu Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20201124161025.27694-3-lukasz.luba@arm.com

thermal: power allocator: change the 'k_i' coefficient estimation

2020-11-26T16:11:59Z

Intelligent Power Allocation (IPA) is built around the PID controller concept. The initialization code tries to setup the environment based on the information available in DT or estimate the value based on minimum power reported by each of the cooling device. The estimation will have an impact on the PID controller behaviour via the related 'k_po', 'k_pu', 'k_i' coefficients and also on the power budget calculation. This change prevents the situation when 'k_i' is relatively big compared to 'k_po' and 'k_pu' values. This might happen when the estimation for 'sustainable_power' returned small value, thus 'k_po' and 'k_pu' are small. Signed-off-by: Lukasz Luba Reviewed-by: Ionela Voinescu Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20201124161025.27694-2-lukasz.luba@arm.com

thermal: core: Move power_actor_set_power into IPA

2020-10-27T08:44:32Z

Since the power actor section has one function power_actor_set_power() move it into Intelligent Power Allocation (IPA). There is no other user of that helper function. It would also allow to remove the check of cdev_is_power_actor() because the code which calls it in IPA already does the needed check. Make the function static since only IPA use it. Signed-off-by: Lukasz Luba Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20201015112441.4056-5-lukasz.luba@arm.com