Hi Oleksij,

On Thu, 21 Oct 2021 at 19:21, Oleksij Rempel [off-list ref] wrote:

Hi Petr,

On Wed, Oct 20, 2021 at 05:53:03PM +0200, Petr Benes wrote:

quoted

On Wed, 20 Oct 2021 at 07:05, Oleksij Rempel [off-list ref] wrote:

quoted

Hi Petr and Michal,

I forgot to add you for v2 in CC. Please test/review this version.

Hi Oleksij,

It works good. with PM as well as without PM. The only minor issue I found is,
that the first temperature reading (when the driver probes) fails. That is
(val & soc_data->temp_valid_mask) == 0) holds true. How does
pm_runtime_resume_and_get() behave in imx_thermal_probe()?
Does it go through imx_thermal_runtime_resume() with usleep_range()?

How exactly did you reproduce it? Even more or less understanding how

I just placed my debug print into get_temp()

    if ((val & soc_data->temp_valid_mask) == 0) {
        dev_dbg(&tz->device, "temp measurement never finished\n");
        printk("Wrong temperature reading!!!!!!\n");
        return -EAGAIN;
    }

this can potentially happen, i never had this issue on my HW. Is it something
HW specific?

IMHO it is just product of the following sequence:

pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(data->dev);
pm_runtime_resume_and_get(data->dev);
thermal_zone_device_enable(data->tz);

With assumption imx_thermal_runtime_resume() didn't run,
hence the sensor didn't get enough time to come up.

I didn't have time to spend it on and you have better knowledge of the
area. If it is not that straightforward I can try to diagnose it better.

Even after executing this command:
echo disabled > /sys/class/thermal/thermal_zone0/mode
cat /sys/class/thermal/thermal_zone0/temp

In this case, IRQ is disabled and on each manual temp read, driver starts
actively using runtime PM. I still never get (val & soc_data->temp_valid_mask)
== 0)..

quoted

quoted

On Tue, Oct 19, 2021 at 03:08:09PM +0200, Oleksij Rempel wrote:

quoted

Starting with commit d92ed2c9d3ff ("thermal: imx: Use driver's local
data to decide whether to run a measurement") this driver stared using
irq_enabled flag to make decision to power on/off the thermal core. This
triggered a regression, where after reaching critical temperature, alarm
IRQ handler set irq_enabled to false,  disabled thermal core and was not
able read temperature and disable cooling sequence.

In case the cooling device is "CPU/GPU freq", the system will run with
reduce performance until next reboot.

To solve this issue, we need to move all parts implementing hand made
runtime power management and let it handle actual runtime PM framework.

Fixes: d92ed2c9d3ff ("thermal: imx: Use driver's local data to decide whether to run a measurement")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/thermal/imx_thermal.c | 143 +++++++++++++++++++++-------------
 1 file changed, 89 insertions(+), 54 deletions(-)

diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
index 2c7473d86a59..cb5a4354fc75 100644
--- a/drivers/thermal/imx_thermal.c
+++ b/drivers/thermal/imx_thermal.c

@@ -15,6 +15,7 @@
 #include <linux/regmap.h>
 #include <linux/thermal.h>
 #include <linux/nvmem-consumer.h>
+#include <linux/pm_runtime.h>

 #define REG_SET              0x4
 #define REG_CLR              0x8

@@ -194,6 +195,7 @@ static struct thermal_soc_data thermal_imx7d_data = {
 };

 struct imx_thermal_data {
+     struct device *dev;
      struct cpufreq_policy *policy;
      struct thermal_zone_device *tz;
      struct thermal_cooling_device *cdev;

@@ -252,44 +254,15 @@ static int imx_get_temp(struct thermal_zone_device *tz, int *temp)
      const struct thermal_soc_data *soc_data = data->socdata;
      struct regmap *map = data->tempmon;
      unsigned int n_meas;
-     bool wait, run_measurement;
      u32 val;
+     int ret;

-     run_measurement = !data->irq_enabled;
-     if (!run_measurement) {
-             /* Check if a measurement is currently in progress */
-             regmap_read(map, soc_data->temp_data, &val);
-             wait = !(val & soc_data->temp_valid_mask);
-     } else {
-             /*
-              * Every time we measure the temperature, we will power on the
-              * temperature sensor, enable measurements, take a reading,
-              * disable measurements, power off the temperature sensor.
-              */
-             regmap_write(map, soc_data->sensor_ctrl + REG_CLR,
-                         soc_data->power_down_mask);
-             regmap_write(map, soc_data->sensor_ctrl + REG_SET,
-                         soc_data->measure_temp_mask);
-
-             wait = true;
-     }
-
-     /*
-      * According to the temp sensor designers, it may require up to ~17us
-      * to complete a measurement.
-      */
-     if (wait)
-             usleep_range(20, 50);
+     ret = pm_runtime_resume_and_get(data->dev);
+     if (ret < 0)
+             return ret;

      regmap_read(map, soc_data->temp_data, &val);

-     if (run_measurement) {
-             regmap_write(map, soc_data->sensor_ctrl + REG_CLR,
-                          soc_data->measure_temp_mask);
-             regmap_write(map, soc_data->sensor_ctrl + REG_SET,
-                          soc_data->power_down_mask);
-     }
-
      if ((val & soc_data->temp_valid_mask) == 0) {
              dev_dbg(&tz->device, "temp measurement never finished\n");
              return -EAGAIN;

@@ -328,6 +301,8 @@ static int imx_get_temp(struct thermal_zone_device *tz, int *temp)
              enable_irq(data->irq);
      }

+     pm_runtime_put(data->dev);
+
      return 0;
 }

@@ -335,24 +310,16 @@ static int imx_change_mode(struct thermal_zone_device *tz,
                         enum thermal_device_mode mode)
 {
      struct imx_thermal_data *data = tz->devdata;
-     struct regmap *map = data->tempmon;
-     const struct thermal_soc_data *soc_data = data->socdata;

      if (mode == THERMAL_DEVICE_ENABLED) {
-             regmap_write(map, soc_data->sensor_ctrl + REG_CLR,
-                          soc_data->power_down_mask);
-             regmap_write(map, soc_data->sensor_ctrl + REG_SET,
-                          soc_data->measure_temp_mask);
+             pm_runtime_get(data->dev);

              if (!data->irq_enabled) {
                      data->irq_enabled = true;
                      enable_irq(data->irq);
              }
      } else {
-             regmap_write(map, soc_data->sensor_ctrl + REG_CLR,
-                          soc_data->measure_temp_mask);
-             regmap_write(map, soc_data->sensor_ctrl + REG_SET,
-                          soc_data->power_down_mask);
+             pm_runtime_put(data->dev);

              if (data->irq_enabled) {
                      disable_irq(data->irq);

@@ -393,6 +360,11 @@ static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip,
                           int temp)
 {
      struct imx_thermal_data *data = tz->devdata;
+     int ret;
+
+     ret = pm_runtime_resume_and_get(data->dev);
+     if (ret < 0)
+             return ret;

      /* do not allow changing critical threshold */
      if (trip == IMX_TRIP_CRITICAL)

@@ -406,6 +378,8 @@ static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip,

      imx_set_alarm_temp(data, temp);

+     pm_runtime_put(data->dev);
+
      return 0;
 }

@@ -681,6 +655,8 @@ static int imx_thermal_probe(struct platform_device *pdev)
      if (!data)
              return -ENOMEM;

+     data->dev = &pdev->dev;
+
      map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon");
      if (IS_ERR(map)) {
              ret = PTR_ERR(map);

@@ -801,6 +777,14 @@ static int imx_thermal_probe(struct platform_device *pdev)
      regmap_write(map, data->socdata->sensor_ctrl + REG_SET,
                   data->socdata->measure_temp_mask);

+     /* the core was configured and enabled just before */
+     pm_runtime_set_active(&pdev->dev);
+     pm_runtime_enable(data->dev);
+
+     ret = pm_runtime_resume_and_get(data->dev);
+     if (ret < 0)
+             goto disable_runtime_pm;
+
      data->irq_enabled = true;
      ret = thermal_zone_device_enable(data->tz);
      if (ret)

@@ -814,10 +798,15 @@ static int imx_thermal_probe(struct platform_device *pdev)
              goto thermal_zone_unregister;
      }

+     pm_runtime_put(data->dev);
+
      return 0;

 thermal_zone_unregister:
      thermal_zone_device_unregister(data->tz);
+disable_runtime_pm:
+     pm_runtime_put_noidle(data->dev);
+     pm_runtime_disable(data->dev);
 clk_disable:
      clk_disable_unprepare(data->thermal_clk);
 legacy_cleanup:

@@ -829,13 +818,9 @@ static int imx_thermal_probe(struct platform_device *pdev)
 static int imx_thermal_remove(struct platform_device *pdev)
 {
      struct imx_thermal_data *data = platform_get_drvdata(pdev);
-     struct regmap *map = data->tempmon;

-     /* Disable measurements */
-     regmap_write(map, data->socdata->sensor_ctrl + REG_SET,
-                  data->socdata->power_down_mask);
-     if (!IS_ERR(data->thermal_clk))
-             clk_disable_unprepare(data->thermal_clk);
+     pm_runtime_put_noidle(data->dev);
+     pm_runtime_disable(data->dev);

      thermal_zone_device_unregister(data->tz);
      imx_thermal_unregister_legacy_cooling(data);

@@ -858,29 +843,79 @@ static int __maybe_unused imx_thermal_suspend(struct device *dev)
      ret = thermal_zone_device_disable(data->tz);
      if (ret)
              return ret;
+
+     return pm_runtime_force_suspend(data->dev);
+}
+
+static int __maybe_unused imx_thermal_resume(struct device *dev)
+{
+     struct imx_thermal_data *data = dev_get_drvdata(dev);
+     int ret;
+
+     ret = pm_runtime_force_resume(data->dev);
+     if (ret)
+             return ret;
+     /* Enabled thermal sensor after resume */
+     return thermal_zone_device_enable(data->tz);
+}
+
+static int __maybe_unused imx_thermal_runtime_suspend(struct device *dev)
+{
+     struct imx_thermal_data *data = dev_get_drvdata(dev);
+     const struct thermal_soc_data *socdata = data->socdata;
+     struct regmap *map = data->tempmon;
+     int ret;
+
+     ret = regmap_write(map, socdata->sensor_ctrl + REG_CLR,
+                        socdata->measure_temp_mask);
+     if (ret)
+             return ret;
+
+     ret = regmap_write(map, socdata->sensor_ctrl + REG_SET,
+                        socdata->power_down_mask);
+     if (ret)
+             return ret;
+
      clk_disable_unprepare(data->thermal_clk);

      return 0;
 }

-static int __maybe_unused imx_thermal_resume(struct device *dev)
+static int __maybe_unused imx_thermal_runtime_resume(struct device *dev)
 {
      struct imx_thermal_data *data = dev_get_drvdata(dev);
+     const struct thermal_soc_data *socdata = data->socdata;
+     struct regmap *map = data->tempmon;
      int ret;

      ret = clk_prepare_enable(data->thermal_clk);
      if (ret)
              return ret;
-     /* Enabled thermal sensor after resume */
-     ret = thermal_zone_device_enable(data->tz);
+
+     ret = regmap_write(map, socdata->sensor_ctrl + REG_CLR,
+                        socdata->power_down_mask);
+     if (ret)
+             return ret;
+
+     ret = regmap_write(map, socdata->sensor_ctrl + REG_SET,
+                        socdata->measure_temp_mask);
      if (ret)
              return ret;

+     /*
+      * According to the temp sensor designers, it may require up to ~17us
+      * to complete a measurement.
+      */
+     usleep_range(20, 50);
+
      return 0;
 }

-static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops,
-                      imx_thermal_suspend, imx_thermal_resume);
+static const struct dev_pm_ops imx_thermal_pm_ops = {
+     SET_SYSTEM_SLEEP_PM_OPS(imx_thermal_suspend, imx_thermal_resume)
+     SET_RUNTIME_PM_OPS(imx_thermal_runtime_suspend,
+                        imx_thermal_runtime_resume, NULL)
+};

 static struct platform_driver imx_thermal = {
      .driver = {
--

2.30.2

--
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

--
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |