linux-kernel - [PATCH 2/2] thermal: cooling: Fix unneeded conversions in cpufreq_cooling and devfreq

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Message-ID: <20240308065922.10329-2-poshao.chen@mediatek.com>
Date: Fri, 8 Mar 2024 14:59:22 +0800
From: PoShao Chen <poshao.chen@...iatek.com>
To: <linux-kernel@...r.kernel.org>, <linux-pm@...r.kernel.org>
CC: <lukasz.luba@....com>, <dietmar.eggemann@....com>, <rafael@...nel.org>,
	<mingo@...nel.org>, <rafael.j.wysocki@...el.com>, <rui.zhang@...el.com>,
	<vincent.guittot@...aro.org>, <daniel.lezcano@...aro.org>,
	<viresh.kumar@...aro.org>, <amit.kachhap@...il.com>,
	<clive.lin@...iatek.com>, <ccj.yeh@...iatek.com>,
	<ching-hao.hsu@...iatek.com>, <poshao.chen@...iatek.com>
Subject: [PATCH 2/2] thermal: cooling: Fix unneeded conversions in cpufreq_cooling and devfreq_cooling

Fix the incorrect division of power values by MICROWATT_PER_MILLIWATT for
non-microwatt units in the Energy Model (EM) by adding an
em_is_microwatts() check. This ensures that power values are only converted
when the EM specifies microwatts, allowing for accurate interpretation of
power according to the unit defined by the EM.

Signed-off-by: PoShao Chen <poshao.chen@...iatek.com>
---
 drivers/thermal/cpufreq_cooling.c |  6 ++++--
 drivers/thermal/devfreq_cooling.c | 12 ++++++++----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c
index 9d1b1459700d..5324b9766843 100644
--- a/drivers/thermal/cpufreq_cooling.c
+++ b/drivers/thermal/cpufreq_cooling.c
@@ -120,7 +120,8 @@ static u32 cpu_freq_to_power(struct cpufreq_cooling_device *cpufreq_cdev,
 	}
 
 	power_mw = table[i + 1].power;
-	power_mw /= MICROWATT_PER_MILLIWATT;
+	if (em_is_microwatts(cpufreq_cdev->em))
+		power_mw /= MICROWATT_PER_MILLIWATT;
 	rcu_read_unlock();
 
 	return power_mw;
@@ -139,7 +140,8 @@ static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev,
 	for (i = cpufreq_cdev->max_level; i > 0; i--) {
 		/* Convert EM power to milli-Watts to make safe comparison */
 		em_power_mw = table[i].power;
-		em_power_mw /= MICROWATT_PER_MILLIWATT;
+		if (em_is_microwatts(cpufreq_cdev->em))
+			em_power_mw /= MICROWATT_PER_MILLIWATT;
 		if (power >= em_power_mw)
 			break;
 	}
diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
index 50dec24e967a..c28e0c4a63d6 100644
--- a/drivers/thermal/devfreq_cooling.c
+++ b/drivers/thermal/devfreq_cooling.c
@@ -222,7 +222,8 @@ static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cd
 			dfc->res_util = table[state].power;
 			rcu_read_unlock();
 
-			dfc->res_util /= MICROWATT_PER_MILLIWATT;
+			if (em_is_microwatts(dfc->em_pd))
+				dfc->res_util /= MICROWATT_PER_MILLIWATT;
 
 			dfc->res_util *= SCALE_ERROR_MITIGATION;
 
@@ -247,7 +248,8 @@ static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cd
 		*power = table[perf_idx].power;
 		rcu_read_unlock();
 
-		*power /= MICROWATT_PER_MILLIWATT;
+		if (em_is_microwatts(dfc->em_pd))
+			*power /= MICROWATT_PER_MILLIWATT;
 		/* Scale power for utilization */
 		*power *= status.busy_time;
 		*power >>= 10;
@@ -279,7 +281,8 @@ static int devfreq_cooling_state2power(struct thermal_cooling_device *cdev,
 	*power = table[perf_idx].power;
 	rcu_read_unlock();
 
-	*power /= MICROWATT_PER_MILLIWATT;
+	if (em_is_microwatts(dfc->em_pd))
+		*power /= MICROWATT_PER_MILLIWATT;
 
 	return 0;
 }
@@ -321,7 +324,8 @@ static int devfreq_cooling_power2state(struct thermal_cooling_device *cdev,
 	for (i = dfc->max_state; i > 0; i--) {
 		/* Convert EM power to milli-Watts to make safe comparison */
 		em_power_mw = table[i].power;
-		em_power_mw /= MICROWATT_PER_MILLIWATT;
+		if (em_is_microwatts(dfc->em_pd))
+			em_power_mw /= MICROWATT_PER_MILLIWATT;
 		if (est_power >= em_power_mw)
 			break;
 	}
-- 
2.18.0