From:   Benjamin Li <benl@squareup.com>
To:     Amit Kucheria <amitk@kernel.org>,
        Thara Gopinath <thara.gopinath@linaro.org>
Cc:     Benjamin Li <benl@squareup.com>, Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Zhang Rui <rui.zhang@intel.com>, linux-pm@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] drivers: thermal: tsens: respect thermal_device_mode in threshold irq reporting
Date:   Thu, 13 Jan 2022 19:17:30 -0800
Message-Id: <20220114031730.25621-1-benl@squareup.com>
Precedence: bulk

'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@squareup.com>
Signed-off-by: Benjamin Li <benl@squareup.com>
---
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