[PATCH v2] drivers: thermal: tsens: respect thermal_device_mode in threshold irq reporting

From: Benjamin Li
Date: Thu Jan 13 2022 - 22:17:39 EST


'echo disabled > .../thermal_zoneX/mode' will disable the thermal core's
polling mechanism to check for threshold trips. This is used sometimes to
run performance test cases.

However, tsens supports an interrupt mechanism to receive notification of
trips, implemented in commit 634e11d5b450 ("drivers: thermal: tsens: Add
interrupt support").

Currently the thermal zone mode that's set by userspace is not checked
before propagating threshold trip events from IRQs. Let's fix this to
restore the abilty to disable thermal throttling at runtime.

====================

Tested on MSM8939 running 5.16.0. This platform has 8 cores; the first
four thermal zones control cpu0-3 and the last zone is for the other four
CPUs together.

for f in /sys/class/thermal/thermal_zone*; do
echo "disabled" > $f/mode
echo $f | paste - $f/type $f/mode
done

/sys/class/thermal/thermal_zone0 cpu0-thermal disabled
/sys/class/thermal/thermal_zone1 cpu1-thermal disabled
/sys/class/thermal/thermal_zone2 cpu2-thermal disabled
/sys/class/thermal/thermal_zone3 cpu3-thermal disabled
/sys/class/thermal/thermal_zone4 cpu4567-thermal disabled

With mitigation thresholds at 75 degC and load running, we can now cruise
past temp=75000 without CPU throttling kicking in.

watch -n 1 "grep '' /sys/class/thermal/*/temp
/sys/class/thermal/*/cur_state
/sys/bus/cpu/devices/cpu*/cpufreq/cpuinfo_cur_freq"

/sys/class/thermal/thermal_zone0/temp:82000
/sys/class/thermal/thermal_zone1/temp:84000
/sys/class/thermal/thermal_zone2/temp:87000
/sys/class/thermal/thermal_zone3/temp:84000
/sys/class/thermal/thermal_zone4/temp:84000
/sys/class/thermal/cooling_device0/cur_state:0
/sys/class/thermal/cooling_device1/cur_state:0
/sys/bus/cpu/devices/cpu0/cpufreq/cpuinfo_cur_freq:1113600
/sys/bus/cpu/devices/cpu1/cpufreq/cpuinfo_cur_freq:1113600
/sys/bus/cpu/devices/cpu2/cpufreq/cpuinfo_cur_freq:1113600
/sys/bus/cpu/devices/cpu3/cpufreq/cpuinfo_cur_freq:1113600
/sys/bus/cpu/devices/cpu4/cpufreq/cpuinfo_cur_freq:800000
/sys/bus/cpu/devices/cpu5/cpufreq/cpuinfo_cur_freq:800000
/sys/bus/cpu/devices/cpu6/cpufreq/cpuinfo_cur_freq:800000
/sys/bus/cpu/devices/cpu7/cpufreq/cpuinfo_cur_freq:800000

Reported-by: Zac Crosby <zac@xxxxxxxxxxxx>
Signed-off-by: Benjamin Li <benl@xxxxxxxxxxxx>
---
Changes in v2:
- Reordered sentences in first part of commit message to make sense.

drivers/thermal/qcom/tsens.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c
index 99a8d9f3e03c..0b6299512e7c 100644
--- a/drivers/thermal/qcom/tsens.c
+++ b/drivers/thermal/qcom/tsens.c
@@ -509,13 +509,16 @@ static irqreturn_t tsens_irq_thread(int irq, void *data)
spin_unlock_irqrestore(&priv->ul_lock, flags);

if (trigger) {
- dev_dbg(priv->dev, "[%u] %s: TZ update trigger (%d mC)\n",
- hw_id, __func__, temp);
- thermal_zone_device_update(s->tzd,
- THERMAL_EVENT_UNSPECIFIED);
+ if (s->tzd->mode == THERMAL_DEVICE_ENABLED) {
+ dev_dbg(priv->dev, "[%u] %s: TZ update trigger (%d mC)\n",
+ hw_id, __func__, temp);
+ thermal_zone_device_update(s->tzd, THERMAL_EVENT_UNSPECIFIED);
+ } else {
+ dev_dbg(priv->dev, "[%u] %s: TZ update trigger (%d mC) skipped as zone disabled\n",
+ hw_id, __func__, temp);
+ }
} else {
- dev_dbg(priv->dev, "[%u] %s: no violation: %d\n",
- hw_id, __func__, temp);
+ dev_dbg(priv->dev, "[%u] %s: no violation: %d\n", hw_id, __func__, temp);
}

if (tsens_version(priv) < VER_0_1) {
--
2.17.1