Commit 2dcd851f authored by Yadwinder Singh Brar's avatar Yadwinder Singh Brar Committed by Eduardo Valentin
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thermal: cpu_cooling: Update always cpufreq policy with thermal constraints 



Existing code updates cupfreq policy only while executing
cpufreq_apply_cooling() function (i.e. when notify_device != NOTIFY_INVALID).
It doesn't apply constraints when cpufreq policy update happens from any other
place but it should update the cpufreq policy with thermal constraints every
time when there is a cpufreq policy update, to keep state of
cpufreq_cooling_device and max_feq of cpufreq policy in sync. For instance
while resuming cpufreq updates cpufreq_policy and it restores default
policy->usr_policy values irrespective of cooling device's cpufreq_state since
notification gets missed because (notify_device == NOTIFY_INVALID).
Another problem, is that userspace is able to change max_freq irrespective of
cooling device's state, as notification gets missed.

This patch modifies code to maintain a global cpufreq_dev_list and applies
constraints of all matching cooling devices for policy's cpu when there is any
policy update(ends up applying the lowest max_freq among the matching cpu
cooling devices).

This patch also removes redundant check (max_freq > policy->user_policy.max),
as cpufreq framework takes care of user_policy constraints already where ever
required, otherwise its causing an issue while increasing max_freq in normal
scenerio as it restores max_freq with policy->user_policy.max which is old
(smaller) value.

Signed-off-by: default avatarYadwinder Singh Brar <yadi.brar@samsung.com>
Signed-off-by: default avatarEduardo Valentin <edubezval@gmail.com>
parent fc14f9c1

drivers/thermal/cpu_cooling.c

+21 −16
Original line number Diff line number Diff line
@@ -50,15 +50,14 @@ struct cpufreq_cooling_device { 
	unsigned int cpufreq_state;

	unsigned int cpufreq_val;

	struct cpumask allowed_cpus;

	struct list_head node;

};

static DEFINE_IDR(cpufreq_idr);

static DEFINE_MUTEX(cooling_cpufreq_lock);



static unsigned int cpufreq_dev_count;



/* notify_table passes value to the CPUFREQ_ADJUST callback function. */

#define NOTIFY_INVALID NULL

static struct cpufreq_cooling_device *notify_device;

static LIST_HEAD(cpufreq_dev_list);



/**

 * get_idr - function to get a unique id.
@@ -287,15 +286,12 @@ static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, 


	cpufreq_device->cpufreq_state = cooling_state;

	cpufreq_device->cpufreq_val = clip_freq;

	notify_device = cpufreq_device;



	for_each_cpu(cpuid, mask) {

		if (is_cpufreq_valid(cpuid))

			cpufreq_update_policy(cpuid);

	}



	notify_device = NOTIFY_INVALID;



	return 0;

}
@@ -316,21 +312,28 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb, 
{

	struct cpufreq_policy *policy = data;

	unsigned long max_freq = 0;

	struct cpufreq_cooling_device *cpufreq_dev;



	if (event != CPUFREQ_ADJUST || notify_device == NOTIFY_INVALID)

	if (event != CPUFREQ_ADJUST)

		return 0;



	if (cpumask_test_cpu(policy->cpu, &notify_device->allowed_cpus))

		max_freq = notify_device->cpufreq_val;

	else

		return 0;

	mutex_lock(&cooling_cpufreq_lock);

	list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) {

		if (!cpumask_test_cpu(policy->cpu,

					&cpufreq_dev->allowed_cpus))

			continue;



		if (!cpufreq_dev->cpufreq_val)

			cpufreq_dev->cpufreq_val = get_cpu_frequency(

					cpumask_any(&cpufreq_dev->allowed_cpus),

					cpufreq_dev->cpufreq_state);



	/* Never exceed user_policy.max */

	if (max_freq > policy->user_policy.max)

		max_freq = policy->user_policy.max;

		max_freq = cpufreq_dev->cpufreq_val;



		if (policy->max != max_freq)

			cpufreq_verify_within_limits(policy, 0, max_freq);

	}

	mutex_unlock(&cooling_cpufreq_lock);



	return 0;

}
@@ -486,6 +489,7 @@ __cpufreq_cooling_register(struct device_node *np, 
		cpufreq_register_notifier(&thermal_cpufreq_notifier_block,

					  CPUFREQ_POLICY_NOTIFIER);

	cpufreq_dev_count++;

	list_add(&cpufreq_dev->node, &cpufreq_dev_list);



	mutex_unlock(&cooling_cpufreq_lock);
@@ -549,6 +553,7 @@ void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) 


	cpufreq_dev = cdev->devdata;

	mutex_lock(&cooling_cpufreq_lock);

	list_del(&cpufreq_dev->node);

	cpufreq_dev_count--;



	/* Unregister the notifier for the last cpufreq cooling device */

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