Thread (9 messages) 9 messages, 2 authors, 2018-01-17
STALE3070d
Revisions (2)
  1. v1 [diff vs current]
  2. v2 current

[PATCH v2 2/2] thermal: cpu_cooling: use power models from the OPP library

From: Quentin Perret <hidden>
Date: 2018-01-16 16:51:57
Subsystem: the rest, thermal · Maintainers: Linus Torvalds, Rafael J. Wysocki, Daniel Lezcano

Now that the OPP library features a power estimator, the existing code
in IPA can be modified to rely only on dev_pm_opp_get_power() without
having to care about the dynamic-power-coefficient DT binding.

Signed-off-by: Quentin Perret <redacted>
---
 drivers/thermal/cpu_cooling.c | 33 +++++++++------------------------
 1 file changed, 9 insertions(+), 24 deletions(-)
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index dfd23245f778..b961bd6a198b 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -187,7 +187,6 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb,
 /**
  * update_freq_table() - Update the freq table with power numbers
  * @cpufreq_cdev:	the cpufreq cooling device in which to update the table
- * @capacitance: dynamic power coefficient for these cpus
  *
  * Update the freq table with power numbers.  This table will be used in
  * cpu_power_to_freq() and cpu_freq_to_power() to convert between power and
@@ -197,8 +196,7 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb,
  * Return: 0 on success, -EINVAL if there are no OPPs for any CPUs,
  * or -ENOMEM if we run out of memory.
  */
-static int update_freq_table(struct cpufreq_cooling_device *cpufreq_cdev,
-			     u32 capacitance)
+static int update_freq_table(struct cpufreq_cooling_device *cpufreq_cdev)
 {
 	struct freq_table *freq_table = cpufreq_cdev->freq_table;
 	struct dev_pm_opp *opp;
@@ -227,9 +225,6 @@ static int update_freq_table(struct cpufreq_cooling_device *cpufreq_cdev,
 
 	for (i = 0; i <= cpufreq_cdev->max_level; i++) {
 		unsigned long freq = freq_table[i].frequency * 1000;
-		u32 freq_mhz = freq_table[i].frequency / 1000;
-		u64 power;
-		u32 voltage_mv;
 
 		/*
 		 * Find ceil frequency as 'freq' may be slightly lower than OPP
@@ -242,18 +237,9 @@ static int update_freq_table(struct cpufreq_cooling_device *cpufreq_cdev,
 			return -EINVAL;
 		}
 
-		voltage_mv = dev_pm_opp_get_voltage(opp) / 1000;
-		dev_pm_opp_put(opp);
-
-		/*
-		 * Do the multiplication with MHz and millivolt so as
-		 * to not overflow.
-		 */
-		power = (u64)capacitance * freq_mhz * voltage_mv * voltage_mv;
-		do_div(power, 1000000000);
-
 		/* power is stored in mW */
-		freq_table[i].power = power;
+		freq_table[i].power = dev_pm_opp_get_power(opp) / 1000;
+		dev_pm_opp_put(opp);
 	}
 
 	return 0;
@@ -606,7 +592,7 @@ static unsigned int find_next_max(struct cpufreq_frequency_table *table,
  */
 static struct thermal_cooling_device *
 __cpufreq_cooling_register(struct device_node *np,
-			struct cpufreq_policy *policy, u32 capacitance)
+			struct cpufreq_policy *policy, bool power_model)
 {
 	struct thermal_cooling_device *cdev;
 	struct cpufreq_cooling_device *cpufreq_cdev;
@@ -675,8 +661,8 @@ __cpufreq_cooling_register(struct device_node *np,
 			pr_debug("%s: freq:%u KHz\n", __func__, freq);
 	}
 
-	if (capacitance) {
-		ret = update_freq_table(cpufreq_cdev, capacitance);
+	if (power_model) {
+		ret = update_freq_table(cpufreq_cdev);
 		if (ret) {
 			cdev = ERR_PTR(ret);
 			goto remove_ida;
@@ -760,7 +746,7 @@ of_cpufreq_cooling_register(struct cpufreq_policy *policy)
 {
 	struct device_node *np = of_get_cpu_node(policy->cpu, NULL);
 	struct thermal_cooling_device *cdev = NULL;
-	u32 capacitance = 0;
+	bool has_power;
 
 	if (!np) {
 		pr_err("cpu_cooling: OF node not available for cpu%d\n",
@@ -769,10 +755,9 @@ of_cpufreq_cooling_register(struct cpufreq_policy *policy)
 	}
 
 	if (of_find_property(np, "#cooling-cells", NULL)) {
-		of_property_read_u32(np, "dynamic-power-coefficient",
-				     &capacitance);
+		has_power = dev_pm_opp_has_power(get_cpu_device(policy->cpu));
 
-		cdev = __cpufreq_cooling_register(np, policy, capacitance);
+		cdev = __cpufreq_cooling_register(np, policy, has_power);
 		if (IS_ERR(cdev)) {
 			pr_err("cpu_cooling: cpu%d is not running as cooling device: %ld\n",
 			       policy->cpu, PTR_ERR(cdev));
-- 
2.15.1
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