From 2dcd851fe4b4fe60c2f8520bf7668d7e9b2dd76b Mon Sep 17 00:00:00 2001 From: Yadwinder Singh Brar Date: Fri, 7 Nov 2014 19:12:29 +0530 Subject: [PATCH] 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: Yadwinder Singh Brar Signed-off-by: Eduardo Valentin --- drivers/thermal/cpu_cooling.c | 37 ++++++++++++++++++++--------------- 1 file changed, 21 insertions(+), 16 deletions(-) diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c index 1ab0018271c5..ad09e51ffae4 100644 --- a/drivers/thermal/cpu_cooling.c +++ b/drivers/thermal/cpu_cooling.c @@ -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, ¬ify_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); + 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 */ -- 2.20.1