[PATCH 2/2] thermal: cooling: Fix unneeded conversions in cpufreq_cooling and devfreq_cooling

From: PoShao Chen
Date: Fri Mar 08 2024 - 02:03:21 EST


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@xxxxxxxxxxxx>
---
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