linux-kernel - Re: [PATCH] thermal/drivers/cpuidle_cooling: Change the set_cur

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Date:   Thu, 17 Sep 2020 09:05:30 +0200
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     zhuguangqing83@...il.com, amit.kachhap@...il.com,
        viresh.kumar@...aro.org, javi.merino@...nel.org,
        rui.zhang@...el.com, amitk@...nel.org, zhuguangqing@...omi.com
Cc:     linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] thermal/drivers/cpuidle_cooling: Change the set_cur_state
 function

On 17/09/2020 08:00, zhuguangqing83@...il.com wrote:
> From: zhuguangqing <zhuguangqing@...omi.com>
> 
> In the function cpuidle_cooling_set_cur_state(), if current_state is
> not equal to state and both current_state and state are greater than
> 0(scene 4 as follows), then maybe it should stop->start or restart
> idle_inject.

Sorry, I don't get it.

It is an update of the state, why do we need to restart the idle
injection ? The state change will be automatically take into account by
the idle injection code at the new injection cycle.

> The scenes changed is as follows,
> 
> scene    current_state    state    action
>  1              0          >0       start
>  2              0          0        do nothing
>  3              >0         0        stop
>  4        >0 && !=state    >0       stop->start or restart
>  5        >0 && ==state    >0       do nothing
> 
> Signed-off-by: zhuguangqing <zhuguangqing@...omi.com>
> ---
>  drivers/thermal/cpuidle_cooling.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/thermal/cpuidle_cooling.c b/drivers/thermal/cpuidle_cooling.c
> index 78e3e8238116..868919ad3dda 100644
> --- a/drivers/thermal/cpuidle_cooling.c
> +++ b/drivers/thermal/cpuidle_cooling.c
> @@ -113,7 +113,7 @@ static int cpuidle_cooling_get_cur_state(struct thermal_cooling_device *cdev,
>  /**
>   * cpuidle_cooling_set_cur_state - Set the current cooling state
>   * @cdev: the thermal cooling device
> - * @state: the target state
> + * @state: the target state, max value is 100
>   *
>   * The function checks first if we are initiating the mitigation which
>   * in turn wakes up all the idle injection tasks belonging to the idle
> @@ -130,6 +130,9 @@ static int cpuidle_cooling_set_cur_state(struct thermal_cooling_device *cdev,
>  	unsigned long current_state = idle_cdev->state;
>  	unsigned int runtime_us, idle_duration_us;
>  
> +	if (state > 100 || current_state == state)
> +		return 0;
> +
>  	idle_cdev->state = state;
>  
>  	idle_inject_get_duration(ii_dev, &runtime_us, &idle_duration_us);
> @@ -140,8 +143,11 @@ static int cpuidle_cooling_set_cur_state(struct thermal_cooling_device *cdev,
>  
>  	if (current_state == 0 && state > 0) {
>  		idle_inject_start(ii_dev);
> -	} else if (current_state > 0 && !state)  {
> +	} else if (current_state > 0 && !state) {
>  		idle_inject_stop(ii_dev);
> +	} else {
> +		idle_inject_stop(ii_dev);
> +		idle_inject_start(ii_dev);
>  	}
>  
>  	return 0;
> 


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