Re: [PATCH 25/26] cpu_cooling: Use cpufreq_dev->freq_table for finding level/freq

[Eduardo Valentin <edubezval@gmail.com>]

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On Fri, Nov 28, 2014 at 03:14:19PM +0530, Viresh Kumar wrote:
> get_property() was an over complicated beast with BUGs. It used to believe that
> cpufreq table is present in ascending or descending order, which might not
> always be true.
> 
> Previous patch has created another freq table in descending order for us and we
> better use it now. With that get_property() simply goes away and another helper
> get_level() comes in.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
>  drivers/thermal/cpu_cooling.c | 96 +++++++------------------------------------
>  1 file changed, 14 insertions(+), 82 deletions(-)
> 
> diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
> index 9a4a323..db4c001 100644
> --- a/drivers/thermal/cpu_cooling.c
> +++ b/drivers/thermal/cpu_cooling.c
> @@ -80,85 +80,27 @@ static struct cpufreq_cooling_device *notify_device;
>  
>  /* Below code defines functions to be used for cpufreq as cooling device */
>  
> -enum cpufreq_cooling_property {
> -	GET_LEVEL,
> -	GET_FREQ,
> -};
> -
>  /**
> - * get_property - fetch a property of interest for a given cpu.
> + * get_level: Find the level for a particular frequency
>   * @cpufreq_dev: cpufreq_dev for which the property is required
> - * @input: query parameter
> - * @output: query return
> - * @property: type of query (frequency, level)
> - *
> - * This is the common function to
> - * 1. translate frequency to cooling state
> - * 2. translate cooling state to frequency
> + * @freq: Frequency
>   *
> - * Note that the code may be not in good shape
> - * but it is written in this way in order to:
> - * a) reduce duplicate code as most of the code can be shared.
> - * b) make sure the logic is consistent when translating between
> - *    cooling states and frequencies.
> - *
> - * Return: 0 on success, -EINVAL when invalid parameters are passed.
> + * Returns: level on success, THERMAL_CSTATE_INVALID on error.
>   */
> -static int get_property(struct cpufreq_cooling_device *cpufreq_dev,
> -			unsigned long input, unsigned int *output,
> -			enum cpufreq_cooling_property property)
> +static unsigned long get_level(struct cpufreq_cooling_device *cpufreq_dev,
> +			       unsigned int freq)
>  {
> -	int i;
> -	unsigned long level = 0;
> -	unsigned int freq = CPUFREQ_ENTRY_INVALID;
> -	int descend = -1;
> -	struct cpufreq_frequency_table *pos, *table;
> -
> -	if (!output)
> -		return -EINVAL;
> +	unsigned long level;
>  
> -	table = cpufreq_frequency_get_table(cpumask_first(&cpufreq_dev->allowed_cpus));
> -	if (!table)
> -		return -EINVAL;
> +	for (level = 0; level <= cpufreq_dev->max_level; level++) {
> +		if (freq == cpufreq_dev->freq_table[level])
> +			return level;
>  
> -	cpufreq_for_each_valid_entry(pos, table) {
> -		/* ignore duplicate entry */
> -		if (freq == pos->frequency)
> -			continue;
> -
> -		/* get the frequency order */
> -		if (freq != CPUFREQ_ENTRY_INVALID && descend == -1)
> -			descend = freq > pos->frequency;
> -
> -		freq = pos->frequency;
> +		if (freq > cpufreq_dev->freq_table[level])
> +			break;
>  	}
>  
> -	if (property == GET_FREQ)
> -		level = descend ? input : (cpufreq_dev->max_level - input);
> -
> -	i = 0;
> -	cpufreq_for_each_valid_entry(pos, table) {
> -		/* ignore duplicate entry */
> -		if (freq == pos->frequency)
> -			continue;
> -
> -		/* now we have a valid frequency entry */
> -		freq = pos->frequency;
> -
> -		if (property == GET_LEVEL && (unsigned int)input == freq) {
> -			/* get level by frequency */
> -			*output = descend ? i : (cpufreq_dev->max_level - i);
> -			return 0;
> -		}
> -		if (property == GET_FREQ && level == i) {
> -			/* get frequency by level */
> -			*output = freq;
> -			return 0;
> -		}
> -		i++;
> -	}
> -
> -	return -EINVAL;
> +	return THERMAL_CSTATE_INVALID;
>  }
>  
>  /**
> @@ -179,14 +121,8 @@ unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
>  	mutex_lock(&cooling_cpufreq_lock);
>  	list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, head) {
>  		if (cpumask_test_cpu(cpu, &cpufreq_dev->allowed_cpus)) {
> -			unsigned int val;
> -
>  			mutex_unlock(&cooling_cpufreq_lock);
> -			if (get_property(cpufreq_dev, (unsigned long)freq, &val,
> -					 GET_LEVEL))
> -				return THERMAL_CSTATE_INVALID;
> -
> -			return (unsigned long)val;
> +			return get_level(cpufreq_dev, freq);
>  		}
>  	}
>  	mutex_unlock(&cooling_cpufreq_lock);
> @@ -289,16 +225,12 @@ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
>  	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
>  	unsigned int cpu = cpumask_any(&cpufreq_device->allowed_cpus);
>  	unsigned int clip_freq;
> -	int ret = 0;
>  
>  	/* Check if the old cooling action is same as new cooling action */
>  	if (cpufreq_device->cpufreq_state == state)
>  		return 0;
>  
> -	ret = get_property(cpufreq_device, state, &clip_freq, GET_FREQ);
> -	if (ret)
> -		return ret;
> -
> +	clip_freq = cpufreq_device->freq_table[state];

There should be some check for valid state here..

>  	cpufreq_device->cpufreq_state = state;
>  	cpufreq_device->cpufreq_val = clip_freq;
>  	notify_device = cpufreq_device;
> -- 
> 2.0.3.693.g996b0fd
> 

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