thermal: cpu_cooling: Store frequencies in descending order
CPUFreq framework *doesn't* guarantee that frequencies present in cpufreq table
will be in ascending or descending order. But cpu_cooling somehow assumes that.
Probably because most of current users are creating this list from DT, which is
done with the help of OPP layer. And OPP layer creates the list in ascending
order of frequencies.
But cpu_cooling can be used for other platforms too, which don't have
frequencies arranged in any order.
This patch tries to fix this issue by creating another list of valid frequencies
in descending order. Care is also taken to throw warnings for duplicate entries.
Later patches would use it to simplify code.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index 7687922..cb5a4b9 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -65,6 +65,7 @@
unsigned int cpufreq_state;
unsigned int cpufreq_val;
unsigned int max_level;
+ unsigned int *freq_table; /* In descending order */
struct cpumask allowed_cpus;
struct list_head node;
};
@@ -352,6 +353,20 @@
.notifier_call = cpufreq_thermal_notifier,
};
+static unsigned int find_next_max(struct cpufreq_frequency_table *table,
+ unsigned int prev_max)
+{
+ struct cpufreq_frequency_table *pos;
+ unsigned int max = 0;
+
+ cpufreq_for_each_valid_entry(pos, table) {
+ if (pos->frequency > max && pos->frequency < prev_max)
+ max = pos->frequency;
+ }
+
+ return max;
+}
+
/**
* __cpufreq_cooling_register - helper function to create cpufreq cooling device
* @np: a valid struct device_node to the cooling device device tree node
@@ -374,6 +389,7 @@
struct cpufreq_cooling_device *cpufreq_dev;
char dev_name[THERMAL_NAME_LENGTH];
struct cpufreq_frequency_table *pos, *table;
+ unsigned int freq, i;
int ret;
table = cpufreq_frequency_get_table(cpumask_first(clip_cpus));
@@ -397,6 +413,14 @@
cpufreq_for_each_valid_entry(pos, table)
cpufreq_dev->max_level++;
+ cpufreq_dev->freq_table = kmalloc(sizeof(*cpufreq_dev->freq_table) *
+ cpufreq_dev->max_level, GFP_KERNEL);
+ if (!cpufreq_dev->freq_table) {
+ return ERR_PTR(-ENOMEM);
+ cool_dev = ERR_PTR(-ENOMEM);
+ goto free_cdev;
+ }
+
/* max_level is an index, not a counter */
cpufreq_dev->max_level--;
@@ -405,7 +429,7 @@
ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
if (ret) {
cool_dev = ERR_PTR(ret);
- goto free_cdev;
+ goto free_table;
}
snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
@@ -416,6 +440,18 @@
if (IS_ERR(cool_dev))
goto remove_idr;
+ /* Fill freq-table in descending order of frequencies */
+ for (i = 0, freq = -1; i <= cpufreq_dev->max_level; i++) {
+ freq = find_next_max(table, freq);
+ cpufreq_dev->freq_table[i] = freq;
+
+ /* Warn for duplicate entries */
+ if (!freq)
+ pr_warn("%s: table has duplicate entries\n", __func__);
+ else
+ pr_debug("%s: freq:%u KHz\n", __func__, freq);
+ }
+
cpufreq_dev->cool_dev = cool_dev;
mutex_lock(&cooling_cpufreq_lock);
@@ -432,6 +468,8 @@
remove_idr:
release_idr(&cpufreq_idr, cpufreq_dev->id);
+free_table:
+ kfree(cpufreq_dev->freq_table);
free_cdev:
kfree(cpufreq_dev);
@@ -505,6 +543,7 @@
thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
release_idr(&cpufreq_idr, cpufreq_dev->id);
+ kfree(cpufreq_dev->freq_table);
kfree(cpufreq_dev);
}
EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);