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[PATCH 01/13] thermal/drivers/hisi: Fix missing interrupt enablement

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  [PATCH 01/13] thermal/drivers/hisi: Fix missing interrupt enablement Daniel Lezcano <daniel.lezcano@linaro.org> - 2017-08-30 10:50 +0200
    [PATCH 02/13] thermal/drivers/hisi: Remove the multiple sensors support Daniel Lezcano <daniel.lezcano@linaro.org> - 2017-08-30 10:50 +0200
      Re: [PATCH 02/13] thermal/drivers/hisi: Remove the multiple sensors  support Leo Yan <leo.yan@linaro.org> - 2017-09-01 16:10 +0200
        Re: [PATCH 02/13] thermal/drivers/hisi: Remove the multiple sensors  support Daniel Lezcano <daniel.lezcano@linaro.org> - 2017-09-01 22:50 +0200
    [PATCH 06/13] thermal/drivers/hisi: Remove pointless lock Daniel Lezcano <daniel.lezcano@linaro.org> - 2017-08-30 11:00 +0200
      Re: [PATCH 06/13] thermal/drivers/hisi: Remove pointless lock Leo Yan <leo.yan@linaro.org> - 2017-09-01 16:50 +0200
    [PATCH 03/13] thermal/drivers/hisi: Fix kernel panic on alarm interrupt Daniel Lezcano <daniel.lezcano@linaro.org> - 2017-08-30 11:00 +0200
      Re: [PATCH 03/13] thermal/drivers/hisi: Fix kernel panic on alarm  interrupt Leo Yan <leo.yan@linaro.org> - 2017-09-01 16:20 +0200
    [PATCH 08/13] thermal/drivers/hisi: Fix configuration register setting Daniel Lezcano <daniel.lezcano@linaro.org> - 2017-08-30 11:00 +0200
      Re: [PATCH 08/13] thermal/drivers/hisi: Fix configuration register  setting Leo Yan <leo.yan@linaro.org> - 2017-09-02 05:00 +0200
        Re: [PATCH 08/13] thermal/drivers/hisi: Fix configuration register  setting Daniel Lezcano <daniel.lezcano@linaro.org> - 2017-09-02 10:40 +0200
          Re: [PATCH 08/13] thermal/drivers/hisi: Fix configuration register  setting Leo Yan <leo.yan@linaro.org> - 2017-09-04 03:00 +0200
            Re: [PATCH 08/13] thermal/drivers/hisi: Fix configuration register  setting Daniel Lezcano <daniel.lezcano@linaro.org> - 2017-09-04 11:20 +0200
    [PATCH 09/13] thermal/drivers/hisi: Remove costly sensor inspection Daniel Lezcano <daniel.lezcano@linaro.org> - 2017-08-30 11:00 +0200
      Re: [PATCH 09/13] thermal/drivers/hisi: Remove costly sensor  inspection Leo Yan <leo.yan@linaro.org> - 2017-09-02 05:30 +0200
        Re: [PATCH 09/13] thermal/drivers/hisi: Remove costly sensor  inspection Daniel Lezcano <daniel.lezcano@linaro.org> - 2017-09-02 15:20 +0200
          Re: [PATCH 09/13] thermal/drivers/hisi: Remove costly sensor  inspection Leo Yan <leo.yan@linaro.org> - 2017-09-04 03:00 +0200
            Re: [PATCH 09/13] thermal/drivers/hisi: Remove costly sensor  inspection Daniel Lezcano <daniel.lezcano@linaro.org> - 2017-09-04 13:30 +0200
              Re: [PATCH 09/13] thermal/drivers/hisi: Remove costly sensor  inspection Leo Yan <leo.yan@linaro.org> - 2017-09-04 16:40 +0200
    [PATCH 05/13] thermal/drivers/hisi: Fix multiple alarm interrupts firing Daniel Lezcano <daniel.lezcano@linaro.org> - 2017-08-30 11:00 +0200
      Re: [PATCH 05/13] thermal/drivers/hisi: Fix multiple alarm  interrupts firing Leo Yan <leo.yan@linaro.org> - 2017-09-01 16:50 +0200
    Re: [PATCH 01/13] thermal/drivers/hisi: Fix missing interrupt  enablement Leo Yan <leo.yan@linaro.org> - 2017-09-01 10:40 +0200

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#1723121 — [PATCH 01/13] thermal/drivers/hisi: Fix missing interrupt enablement

The interrupt for the temperature threshold is not enabled at the end of the
probe function, enable it after the setup is complete.

On the other side, the irq_enabled is not correctly set as we are checking if
the interrupt is masked where 'yes' means irq_enabled=false.

	irq_get_irqchip_state(data->irq, IRQCHIP_STATE_MASKED,
				&data->irq_enabled);

As we are always enabling the interrupt, it is pointless to check if
the interrupt is masked or not, just set irq_enabled to 'true'.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/thermal/hisi_thermal.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
index bd3572c..8381696 100644
--- a/drivers/thermal/hisi_thermal.c
+++ b/drivers/thermal/hisi_thermal.c
@@ -345,8 +345,7 @@ static int hisi_thermal_probe(struct platform_device *pdev)
 	}
 
 	hisi_thermal_enable_bind_irq_sensor(data);
-	irq_get_irqchip_state(data->irq, IRQCHIP_STATE_MASKED,
-			      &data->irq_enabled);
+	data->irq_enabled = true;
 
 	for (i = 0; i < HISI_MAX_SENSORS; ++i) {
 		ret = hisi_thermal_register_sensor(pdev, data,
@@ -358,6 +357,8 @@ static int hisi_thermal_probe(struct platform_device *pdev)
 			hisi_thermal_toggle_sensor(&data->sensors[i], true);
 	}
 
+	enable_irq(data->irq);
+
 	return 0;
 }
 
-- 
2.7.4

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#1723123 — [PATCH 02/13] thermal/drivers/hisi: Remove the multiple sensors support

By essence, the tsensor does not really support multiple sensor at the same
time. It allows to set a sensor and use it to get the temperature, another
sensor could be switched but with a delay of 3-5ms. It is difficult to read
simultaneously several sensors without a big delay.

Today, just one sensor is used, it is not necessary to deal with multiple
sensors in the code. Remove them and if it is needed in the future add them
on top of a code which will be clean up in the meantime.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/thermal/hisi_thermal.c | 77 +++++++++++-------------------------------
 1 file changed, 20 insertions(+), 57 deletions(-)

diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
index 8381696..92b6889 100644
--- a/drivers/thermal/hisi_thermal.c
+++ b/drivers/thermal/hisi_thermal.c
@@ -39,6 +39,7 @@
 #define HISI_TEMP_RESET			(100000)
 
 #define HISI_MAX_SENSORS		4
+#define HISI_DEFAULT_SENSOR		2
 
 struct hisi_thermal_sensor {
 	struct hisi_thermal_data *thermal;
@@ -53,11 +54,10 @@ struct hisi_thermal_data {
 	struct mutex thermal_lock;    /* protects register data */
 	struct platform_device *pdev;
 	struct clk *clk;
-	struct hisi_thermal_sensor sensors[HISI_MAX_SENSORS];
-
-	int irq, irq_bind_sensor;
+	struct hisi_thermal_sensor sensors;
+	int irq;
 	bool irq_enabled;
-
+	
 	void __iomem *regs;
 };
 
@@ -113,7 +113,7 @@ static void hisi_thermal_enable_bind_irq_sensor
 
 	mutex_lock(&data->thermal_lock);
 
-	sensor = &data->sensors[data->irq_bind_sensor];
+	sensor = &data->sensors;
 
 	/* setting the hdak time */
 	writel(0x0, data->regs + TEMP0_CFG);
@@ -160,31 +160,8 @@ static int hisi_thermal_get_temp(void *_sensor, int *temp)
 	struct hisi_thermal_sensor *sensor = _sensor;
 	struct hisi_thermal_data *data = sensor->thermal;
 
-	int sensor_id = -1, i;
-	long max_temp = 0;
-
 	*temp = hisi_thermal_get_sensor_temp(data, sensor);
 
-	sensor->sensor_temp = *temp;
-
-	for (i = 0; i < HISI_MAX_SENSORS; i++) {
-		if (!data->sensors[i].tzd)
-			continue;
-
-		if (data->sensors[i].sensor_temp >= max_temp) {
-			max_temp = data->sensors[i].sensor_temp;
-			sensor_id = i;
-		}
-	}
-
-	/* If no sensor has been enabled, then skip to enable irq */
-	if (sensor_id == -1)
-		return 0;
-
-	mutex_lock(&data->thermal_lock);
-	data->irq_bind_sensor = sensor_id;
-	mutex_unlock(&data->thermal_lock);
-
 	dev_dbg(&data->pdev->dev, "id=%d, irq=%d, temp=%d, thres=%d\n",
 		sensor->id, data->irq_enabled, *temp, sensor->thres_temp);
 	/*
@@ -197,7 +174,7 @@ static int hisi_thermal_get_temp(void *_sensor, int *temp)
 		return 0;
 	}
 
-	if (max_temp < sensor->thres_temp) {
+	if (*temp < sensor->thres_temp) {
 		data->irq_enabled = true;
 		hisi_thermal_enable_bind_irq_sensor(data);
 		enable_irq(data->irq);
@@ -224,22 +201,16 @@ static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
 {
 	struct hisi_thermal_data *data = dev;
 	struct hisi_thermal_sensor *sensor;
-	int i;
 
 	mutex_lock(&data->thermal_lock);
-	sensor = &data->sensors[data->irq_bind_sensor];
+	sensor = &data->sensors;
 
 	dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",
 		 sensor->thres_temp / 1000);
 	mutex_unlock(&data->thermal_lock);
 
-	for (i = 0; i < HISI_MAX_SENSORS; i++) {
-		if (!data->sensors[i].tzd)
-			continue;
-
-		thermal_zone_device_update(data->sensors[i].tzd,
-					   THERMAL_EVENT_UNSPECIFIED);
-	}
+	thermal_zone_device_update(data->sensors.tzd,
+				   THERMAL_EVENT_UNSPECIFIED);
 
 	return IRQ_HANDLED;
 }
@@ -296,7 +267,6 @@ static int hisi_thermal_probe(struct platform_device *pdev)
 {
 	struct hisi_thermal_data *data;
 	struct resource *res;
-	int i;
 	int ret;
 
 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
@@ -347,16 +317,17 @@ static int hisi_thermal_probe(struct platform_device *pdev)
 	hisi_thermal_enable_bind_irq_sensor(data);
 	data->irq_enabled = true;
 
-	for (i = 0; i < HISI_MAX_SENSORS; ++i) {
-		ret = hisi_thermal_register_sensor(pdev, data,
-						   &data->sensors[i], i);
-		if (ret)
-			dev_err(&pdev->dev,
-				"failed to register thermal sensor: %d\n", ret);
-		else
-			hisi_thermal_toggle_sensor(&data->sensors[i], true);
+	ret = hisi_thermal_register_sensor(pdev, data,
+					   &data->sensors,
+					   HISI_DEFAULT_SENSOR);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register thermal sensor: %d\n",
+			ret);
+		return ret;
 	}
 
+	hisi_thermal_toggle_sensor(&data->sensors, true);
+
 	enable_irq(data->irq);
 
 	return 0;
@@ -365,17 +336,9 @@ static int hisi_thermal_probe(struct platform_device *pdev)
 static int hisi_thermal_remove(struct platform_device *pdev)
 {
 	struct hisi_thermal_data *data = platform_get_drvdata(pdev);
-	int i;
-
-	for (i = 0; i < HISI_MAX_SENSORS; i++) {
-		struct hisi_thermal_sensor *sensor = &data->sensors[i];
-
-		if (!sensor->tzd)
-			continue;
-
-		hisi_thermal_toggle_sensor(sensor, false);
-	}
+	struct hisi_thermal_sensor *sensor = &data->sensors;
 
+	hisi_thermal_toggle_sensor(sensor, false);
 	hisi_thermal_disable_sensor(data);
 	clk_disable_unprepare(data->clk);
 
-- 
2.7.4

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#1725117 — Re: [PATCH 02/13] thermal/drivers/hisi: Remove the multiple sensors support

Hi Daniel,

On Wed, Aug 30, 2017 at 10:47:26AM +0200, Daniel Lezcano wrote:
> By essence, the tsensor does not really support multiple sensor at the same
> time. It allows to set a sensor and use it to get the temperature, another
> sensor could be switched but with a delay of 3-5ms. It is difficult to read
> simultaneously several sensors without a big delay.
> 
> Today, just one sensor is used, it is not necessary to deal with multiple
> sensors in the code. Remove them and if it is needed in the future add them
> on top of a code which will be clean up in the meantime.
> 
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
>  drivers/thermal/hisi_thermal.c | 77 +++++++++++-------------------------------
>  1 file changed, 20 insertions(+), 57 deletions(-)
> 
> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
> index 8381696..92b6889 100644
> --- a/drivers/thermal/hisi_thermal.c
> +++ b/drivers/thermal/hisi_thermal.c
> @@ -39,6 +39,7 @@
>  #define HISI_TEMP_RESET			(100000)
>  
>  #define HISI_MAX_SENSORS		4
> +#define HISI_DEFAULT_SENSOR		2

So if we always set the sensor id 2 as default sensor, that means it's
pointless to bind sensor id in dts. E.g. I change to bind thermal
sensor 0, then it's impossible to bind successfully:

-                               thermal-sensors = <&tsensor 2>;
+                               thermal-sensors = <&tsensor 0>;

It's okay for this change, do you think we need reflect this in DT
binding doc [1] ?

[1] Documentation/devicetree/bindings/thermal/hisilicon-thermal.txt

>  struct hisi_thermal_sensor {
>  	struct hisi_thermal_data *thermal;
> @@ -53,11 +54,10 @@ struct hisi_thermal_data {
>  	struct mutex thermal_lock;    /* protects register data */
>  	struct platform_device *pdev;
>  	struct clk *clk;
> -	struct hisi_thermal_sensor sensors[HISI_MAX_SENSORS];
> -
> -	int irq, irq_bind_sensor;
> +	struct hisi_thermal_sensor sensors;
> +	int irq;
>  	bool irq_enabled;
> -
> +	

Repots whitespace error when I apply patch.

>  	void __iomem *regs;
>  };
>  
> @@ -113,7 +113,7 @@ static void hisi_thermal_enable_bind_irq_sensor
>  
>  	mutex_lock(&data->thermal_lock);
>  
> -	sensor = &data->sensors[data->irq_bind_sensor];
> +	sensor = &data->sensors;
>  
>  	/* setting the hdak time */
>  	writel(0x0, data->regs + TEMP0_CFG);
> @@ -160,31 +160,8 @@ static int hisi_thermal_get_temp(void *_sensor, int *temp)
>  	struct hisi_thermal_sensor *sensor = _sensor;
>  	struct hisi_thermal_data *data = sensor->thermal;
>  
> -	int sensor_id = -1, i;
> -	long max_temp = 0;
> -
>  	*temp = hisi_thermal_get_sensor_temp(data, sensor);
>  
> -	sensor->sensor_temp = *temp;
> -
> -	for (i = 0; i < HISI_MAX_SENSORS; i++) {
> -		if (!data->sensors[i].tzd)
> -			continue;
> -
> -		if (data->sensors[i].sensor_temp >= max_temp) {
> -			max_temp = data->sensors[i].sensor_temp;
> -			sensor_id = i;
> -		}
> -	}
> -
> -	/* If no sensor has been enabled, then skip to enable irq */
> -	if (sensor_id == -1)
> -		return 0;
> -
> -	mutex_lock(&data->thermal_lock);
> -	data->irq_bind_sensor = sensor_id;
> -	mutex_unlock(&data->thermal_lock);
> -
>  	dev_dbg(&data->pdev->dev, "id=%d, irq=%d, temp=%d, thres=%d\n",
>  		sensor->id, data->irq_enabled, *temp, sensor->thres_temp);
>  	/*
> @@ -197,7 +174,7 @@ static int hisi_thermal_get_temp(void *_sensor, int *temp)
>  		return 0;
>  	}
>  
> -	if (max_temp < sensor->thres_temp) {
> +	if (*temp < sensor->thres_temp) {
>  		data->irq_enabled = true;
>  		hisi_thermal_enable_bind_irq_sensor(data);
>  		enable_irq(data->irq);
> @@ -224,22 +201,16 @@ static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
>  {
>  	struct hisi_thermal_data *data = dev;
>  	struct hisi_thermal_sensor *sensor;
> -	int i;
>  
>  	mutex_lock(&data->thermal_lock);
> -	sensor = &data->sensors[data->irq_bind_sensor];
> +	sensor = &data->sensors;
>  
>  	dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",
>  		 sensor->thres_temp / 1000);
>  	mutex_unlock(&data->thermal_lock);
>  
> -	for (i = 0; i < HISI_MAX_SENSORS; i++) {
> -		if (!data->sensors[i].tzd)
> -			continue;
> -
> -		thermal_zone_device_update(data->sensors[i].tzd,
> -					   THERMAL_EVENT_UNSPECIFIED);
> -	}
> +	thermal_zone_device_update(data->sensors.tzd,
> +				   THERMAL_EVENT_UNSPECIFIED);
>  
>  	return IRQ_HANDLED;
>  }
> @@ -296,7 +267,6 @@ static int hisi_thermal_probe(struct platform_device *pdev)
>  {
>  	struct hisi_thermal_data *data;
>  	struct resource *res;
> -	int i;
>  	int ret;
>  
>  	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> @@ -347,16 +317,17 @@ static int hisi_thermal_probe(struct platform_device *pdev)
>  	hisi_thermal_enable_bind_irq_sensor(data);
>  	data->irq_enabled = true;
>  
> -	for (i = 0; i < HISI_MAX_SENSORS; ++i) {
> -		ret = hisi_thermal_register_sensor(pdev, data,
> -						   &data->sensors[i], i);
> -		if (ret)
> -			dev_err(&pdev->dev,
> -				"failed to register thermal sensor: %d\n", ret);
> -		else
> -			hisi_thermal_toggle_sensor(&data->sensors[i], true);
> +	ret = hisi_thermal_register_sensor(pdev, data,
> +					   &data->sensors,
> +					   HISI_DEFAULT_SENSOR);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to register thermal sensor: %d\n",
> +			ret);
> +		return ret;
>  	}
>  
> +	hisi_thermal_toggle_sensor(&data->sensors, true);
> +
>  	enable_irq(data->irq);
>  
>  	return 0;
> @@ -365,17 +336,9 @@ static int hisi_thermal_probe(struct platform_device *pdev)
>  static int hisi_thermal_remove(struct platform_device *pdev)
>  {
>  	struct hisi_thermal_data *data = platform_get_drvdata(pdev);
> -	int i;
> -
> -	for (i = 0; i < HISI_MAX_SENSORS; i++) {
> -		struct hisi_thermal_sensor *sensor = &data->sensors[i];
> -
> -		if (!sensor->tzd)
> -			continue;
> -
> -		hisi_thermal_toggle_sensor(sensor, false);
> -	}
> +	struct hisi_thermal_sensor *sensor = &data->sensors;
>  
> +	hisi_thermal_toggle_sensor(sensor, false);
>  	hisi_thermal_disable_sensor(data);
>  	clk_disable_unprepare(data->clk);
>  
> -- 
> 2.7.4
> 

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#1725340 — Re: [PATCH 02/13] thermal/drivers/hisi: Remove the multiple sensors support

On 01/09/2017 16:05, Leo Yan wrote:
> Hi Daniel,
> 
> On Wed, Aug 30, 2017 at 10:47:26AM +0200, Daniel Lezcano wrote:
>> By essence, the tsensor does not really support multiple sensor at the same
>> time. It allows to set a sensor and use it to get the temperature, another
>> sensor could be switched but with a delay of 3-5ms. It is difficult to read
>> simultaneously several sensors without a big delay.
>>
>> Today, just one sensor is used, it is not necessary to deal with multiple
>> sensors in the code. Remove them and if it is needed in the future add them
>> on top of a code which will be clean up in the meantime.
>>
>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
>> ---
>>  drivers/thermal/hisi_thermal.c | 77 +++++++++++-------------------------------
>>  1 file changed, 20 insertions(+), 57 deletions(-)
>>
>> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
>> index 8381696..92b6889 100644
>> --- a/drivers/thermal/hisi_thermal.c
>> +++ b/drivers/thermal/hisi_thermal.c
>> @@ -39,6 +39,7 @@
>>  #define HISI_TEMP_RESET			(100000)
>>  
>>  #define HISI_MAX_SENSORS		4
>> +#define HISI_DEFAULT_SENSOR		2
> 
> So if we always set the sensor id 2 as default sensor, that means it's
> pointless to bind sensor id in dts. E.g. I change to bind thermal
> sensor 0, then it's impossible to bind successfully:
> 
> -                               thermal-sensors = <&tsensor 2>;
> +                               thermal-sensors = <&tsensor 0>;
> 
> It's okay for this change, do you think we need reflect this in DT
> binding doc [1] ?
> 
> [1] Documentation/devicetree/bindings/thermal/hisilicon-thermal.txt

Actually, the current behavior is to go through all the sensors and
register them. By side effect, we end up by registering a sensor with an
id matching the one specified in the DT, others are failing.

That is because there is something missing in the of-thermal API where
we can't call thermal_zone_of_sensor_register() without a matching index.

That is probably why we have in the drivers/thermal/qoriq_thermal.c file
the qoriq_tmu_get_sensor_id() which inspect the thermal-zone DT
structure for the thermal-sensors and read the sensor's id from there in
order to reuse it for thermal_zone_of_sensor_register(). Needless to say
that is not the right place to do that.

IMHO, as nothing gets changed for the moment on hi6220, we can live with
HISI_DEFAULT_SENSOR until we sort out what to do with
thermal_zone_of_sensor_register().


>>  struct hisi_thermal_sensor {
>>  	struct hisi_thermal_data *thermal;
>> @@ -53,11 +54,10 @@ struct hisi_thermal_data {
>>  	struct mutex thermal_lock;    /* protects register data */
>>  	struct platform_device *pdev;
>>  	struct clk *clk;
>> -	struct hisi_thermal_sensor sensors[HISI_MAX_SENSORS];
>> -
>> -	int irq, irq_bind_sensor;
>> +	struct hisi_thermal_sensor sensors;
>> +	int irq;
>>  	bool irq_enabled;
>> -
>> +	
> 
> Repots whitespace error when I apply patch.

Ok, I will fix that.

[ ... ]

Thanks for the review.

  -- Daniel

-- 
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#1723127 — [PATCH 06/13] thermal/drivers/hisi: Remove pointless lock

The threaded interrupt inspect the sensors structure to look in the temp
threshold field, but this field is read-only in all the code, except in the
probe function before the threaded interrupt is set. In other words there
is not race window in the threaded interrupt when reading the field value.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/thermal/hisi_thermal.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
index 524310d..6f0dab1 100644
--- a/drivers/thermal/hisi_thermal.c
+++ b/drivers/thermal/hisi_thermal.c
@@ -221,14 +221,10 @@ static irqreturn_t hisi_thermal_alarm_irq(int irq, void *dev)
 static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
 {
 	struct hisi_thermal_data *data = dev;
-	struct hisi_thermal_sensor *sensor;
-
-	mutex_lock(&data->thermal_lock);
-	sensor = &data->sensors;
+	struct hisi_thermal_sensor *sensor = &data->sensors;
 
 	dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",
 		 sensor->thres_temp);
-	mutex_unlock(&data->thermal_lock);
 
 	thermal_zone_device_update(data->sensors.tzd,
 				   THERMAL_EVENT_UNSPECIFIED);
-- 
2.7.4

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#1725132 — Re: [PATCH 06/13] thermal/drivers/hisi: Remove pointless lock

On Wed, Aug 30, 2017 at 10:47:30AM +0200, Daniel Lezcano wrote:
> The threaded interrupt inspect the sensors structure to look in the temp
> threshold field, but this field is read-only in all the code, except in the
> probe function before the threaded interrupt is set. In other words there
> is not race window in the threaded interrupt when reading the field value.
> 
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Reviewed-by: Leo Yan <leo.yan@linaro.org>

> ---
>  drivers/thermal/hisi_thermal.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
> index 524310d..6f0dab1 100644
> --- a/drivers/thermal/hisi_thermal.c
> +++ b/drivers/thermal/hisi_thermal.c
> @@ -221,14 +221,10 @@ static irqreturn_t hisi_thermal_alarm_irq(int irq, void *dev)
>  static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
>  {
>  	struct hisi_thermal_data *data = dev;
> -	struct hisi_thermal_sensor *sensor;
> -
> -	mutex_lock(&data->thermal_lock);
> -	sensor = &data->sensors;
> +	struct hisi_thermal_sensor *sensor = &data->sensors;
>  
>  	dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",
>  		 sensor->thres_temp);
> -	mutex_unlock(&data->thermal_lock);
>  
>  	thermal_zone_device_update(data->sensors.tzd,
>  				   THERMAL_EVENT_UNSPECIFIED);
> -- 
> 2.7.4
> 

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#1723128 — [PATCH 03/13] thermal/drivers/hisi: Fix kernel panic on alarm interrupt

The threaded interrupt for the alarm interrupt is requested before the
temperature controller is setup. This one can fire an interrupt immediately
leading to a kernel panic as the sensor data is not initialized.

In order to prevent that, move the threaded irq after the Tsensor is setup.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/thermal/hisi_thermal.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
index 92b6889..67db523 100644
--- a/drivers/thermal/hisi_thermal.c
+++ b/drivers/thermal/hisi_thermal.c
@@ -287,15 +287,6 @@ static int hisi_thermal_probe(struct platform_device *pdev)
 	if (data->irq < 0)
 		return data->irq;
 
-	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
-					hisi_thermal_alarm_irq,
-					hisi_thermal_alarm_irq_thread,
-					0, "hisi_thermal", data);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
-		return ret;
-	}
-
 	platform_set_drvdata(pdev, data);
 
 	data->clk = devm_clk_get(&pdev->dev, "thermal_clk");
@@ -328,6 +319,15 @@ static int hisi_thermal_probe(struct platform_device *pdev)
 
 	hisi_thermal_toggle_sensor(&data->sensors, true);
 
+	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
+					hisi_thermal_alarm_irq,
+					hisi_thermal_alarm_irq_thread,
+					0, "hisi_thermal", data);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
+		return ret;
+	}
+
 	enable_irq(data->irq);
 
 	return 0;
-- 
2.7.4

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#1725119 — Re: [PATCH 03/13] thermal/drivers/hisi: Fix kernel panic on alarm interrupt

On Wed, Aug 30, 2017 at 10:47:27AM +0200, Daniel Lezcano wrote:
> The threaded interrupt for the alarm interrupt is requested before the
> temperature controller is setup. This one can fire an interrupt immediately
> leading to a kernel panic as the sensor data is not initialized.
> 
> In order to prevent that, move the threaded irq after the Tsensor is setup.
> 
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Reviewed-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Leo Yan <leo.yan@linaro.org>

> ---
>  drivers/thermal/hisi_thermal.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
> index 92b6889..67db523 100644
> --- a/drivers/thermal/hisi_thermal.c
> +++ b/drivers/thermal/hisi_thermal.c
> @@ -287,15 +287,6 @@ static int hisi_thermal_probe(struct platform_device *pdev)
>  	if (data->irq < 0)
>  		return data->irq;
>  
> -	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
> -					hisi_thermal_alarm_irq,
> -					hisi_thermal_alarm_irq_thread,
> -					0, "hisi_thermal", data);
> -	if (ret < 0) {
> -		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
> -		return ret;
> -	}
> -
>  	platform_set_drvdata(pdev, data);
>  
>  	data->clk = devm_clk_get(&pdev->dev, "thermal_clk");
> @@ -328,6 +319,15 @@ static int hisi_thermal_probe(struct platform_device *pdev)
>  
>  	hisi_thermal_toggle_sensor(&data->sensors, true);
>  
> +	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
> +					hisi_thermal_alarm_irq,
> +					hisi_thermal_alarm_irq_thread,
> +					0, "hisi_thermal", data);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
> +		return ret;
> +	}
> +

Just reminding for the initialization sequence, could we also move
hisi_thermal_enable_bind_irq_sensor(data) after function
hisi_thermal_register_sensor()? The reason is after we registser
sensor with specified sensor ID, then we can bind irq for the
specified ID, otherwise it will wrongly to bind irq to sensor 0. So
finally we can get result as below:

        ret = hisi_thermal_register_sensor(pdev, data,
                                           &data->sensors,
                                           HISI_DEFAULT_SENSOR);
        if (ret) {
                dev_err(&pdev->dev, "failed to register thermal sensor: %d\n",
                        ret);
                return ret;
        }

        hisi_thermal_enable_bind_irq_sensor(data);
        hisi_thermal_toggle_sensor(&data->sensors, true);
        data->irq_enabled = true;

        ret = devm_request_threaded_irq(&pdev->dev, data->irq,
                                        hisi_thermal_alarm_irq,
                                        hisi_thermal_alarm_irq_thread,
                                        0, "hisi_thermal", data);
        if (ret < 0) {
                dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
                return ret;
        }

>  	enable_irq(data->irq);
>  
>  	return 0;
> -- 
> 2.7.4
> 

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#1723129 — [PATCH 08/13] thermal/drivers/hisi: Fix configuration register setting

The TEMP0_CFG configuration register contains different field to set up the
temperature controller. However in the code, nothing prevents a setup to
overwrite the previous one: eg. writing the hdak value overwrites the sensor
selection, the sensor selection overwrites the hdak value.

In order to prevent such thing, use a regmap-like mechanism by reading the
value before, set the corresponding bits and write the result.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/thermal/hisi_thermal.c | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
index d77a938..3e03908 100644
--- a/drivers/thermal/hisi_thermal.c
+++ b/drivers/thermal/hisi_thermal.c
@@ -132,19 +132,39 @@ static inline void hisi_thermal_enable(void __iomem *addr, int value)
 	writel(value, addr + TEMP0_EN);
 }
 
-static inline void hisi_thermal_sensor_select(void __iomem *addr, int sensor)
+static inline int hisi_thermal_get_temperature(void __iomem *addr)
 {
-	writel((sensor << 12), addr + TEMP0_CFG);
+	return hisi_thermal_step_to_temp(readl(addr + TEMP0_VALUE));
 }
 
-static inline int hisi_thermal_get_temperature(void __iomem *addr)
+/*
+ * Temperature configuration register - Sensor selection
+ *
+ * Bits [19:12]
+ *
+ * 0x0: local sensor (default)
+ * 0x1: remote sensor 1 (ACPU cluster 1)
+ * 0x2: remote sensor 2 (ACPU cluster 0)
+ * 0x3: remote sensor 3 (G3D)
+ */
+static inline void hisi_thermal_sensor_select(void __iomem *addr, int sensor)
 {
-	return hisi_thermal_step_to_temp(readl(addr + TEMP0_VALUE));
+	writel(readl(addr + TEMP0_CFG) | (sensor << 12), addr + TEMP0_CFG);
 }
 
+/*
+ * Temperature configuration register - Hdak conversion polling interval
+ *
+ * Bits [5:4]
+ *
+ * 0x0 :   0.768 ms
+ * 0x1 :   6.144 ms
+ * 0x2 :  49.152 ms
+ * 0x3 : 393.216 ms
+ */
 static inline void hisi_thermal_hdak_set(void __iomem *addr, int value)
 {
-	writel(value, addr + TEMP0_CFG);
+	writel(readl(addr + TEMP0_CFG) | (value << 4), addr + TEMP0_CFG);
 }
 
 static long hisi_thermal_get_sensor_temp(struct hisi_thermal_data *data,
-- 
2.7.4

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#1725427 — Re: [PATCH 08/13] thermal/drivers/hisi: Fix configuration register setting

On Wed, Aug 30, 2017 at 10:47:32AM +0200, Daniel Lezcano wrote:
> The TEMP0_CFG configuration register contains different field to set up the
> temperature controller. However in the code, nothing prevents a setup to
> overwrite the previous one: eg. writing the hdak value overwrites the sensor
> selection, the sensor selection overwrites the hdak value.
> 
> In order to prevent such thing, use a regmap-like mechanism by reading the
> value before, set the corresponding bits and write the result.
> 
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
>  drivers/thermal/hisi_thermal.c | 30 +++++++++++++++++++++++++-----
>  1 file changed, 25 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
> index d77a938..3e03908 100644
> --- a/drivers/thermal/hisi_thermal.c
> +++ b/drivers/thermal/hisi_thermal.c
> @@ -132,19 +132,39 @@ static inline void hisi_thermal_enable(void __iomem *addr, int value)
>  	writel(value, addr + TEMP0_EN);
>  }
>  
> -static inline void hisi_thermal_sensor_select(void __iomem *addr, int sensor)
> +static inline int hisi_thermal_get_temperature(void __iomem *addr)
>  {
> -	writel((sensor << 12), addr + TEMP0_CFG);
> +	return hisi_thermal_step_to_temp(readl(addr + TEMP0_VALUE));
>  }
>  
> -static inline int hisi_thermal_get_temperature(void __iomem *addr)
> +/*
> + * Temperature configuration register - Sensor selection
> + *
> + * Bits [19:12]
> + *
> + * 0x0: local sensor (default)
> + * 0x1: remote sensor 1 (ACPU cluster 1)
> + * 0x2: remote sensor 2 (ACPU cluster 0)
> + * 0x3: remote sensor 3 (G3D)
> + */
> +static inline void hisi_thermal_sensor_select(void __iomem *addr, int sensor)
>  {
> -	return hisi_thermal_step_to_temp(readl(addr + TEMP0_VALUE));
> +	writel(readl(addr + TEMP0_CFG) | (sensor << 12), addr + TEMP0_CFG);

nitpick: maybe it's better to firstly clear related bits and then set
value?

>  }
>  
> +/*
> + * Temperature configuration register - Hdak conversion polling interval
> + *
> + * Bits [5:4]
> + *
> + * 0x0 :   0.768 ms
> + * 0x1 :   6.144 ms
> + * 0x2 :  49.152 ms
> + * 0x3 : 393.216 ms
> + */
>  static inline void hisi_thermal_hdak_set(void __iomem *addr, int value)
>  {
> -	writel(value, addr + TEMP0_CFG);
> +	writel(readl(addr + TEMP0_CFG) | (value << 4), addr + TEMP0_CFG);

Ditto.

>  }
>  
>  static long hisi_thermal_get_sensor_temp(struct hisi_thermal_data *data,
> -- 
> 2.7.4
> 

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#1725469 — Re: [PATCH 08/13] thermal/drivers/hisi: Fix configuration register setting

On 02/09/2017 04:54, Leo Yan wrote:
> On Wed, Aug 30, 2017 at 10:47:32AM +0200, Daniel Lezcano wrote:
>> The TEMP0_CFG configuration register contains different field to set up the
>> temperature controller. However in the code, nothing prevents a setup to
>> overwrite the previous one: eg. writing the hdak value overwrites the sensor
>> selection, the sensor selection overwrites the hdak value.
>>
>> In order to prevent such thing, use a regmap-like mechanism by reading the
>> value before, set the corresponding bits and write the result.
>>
>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
>> ---
>>  drivers/thermal/hisi_thermal.c | 30 +++++++++++++++++++++++++-----
>>  1 file changed, 25 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
>> index d77a938..3e03908 100644
>> --- a/drivers/thermal/hisi_thermal.c
>> +++ b/drivers/thermal/hisi_thermal.c
>> @@ -132,19 +132,39 @@ static inline void hisi_thermal_enable(void __iomem *addr, int value)
>>  	writel(value, addr + TEMP0_EN);
>>  }
>>  
>> -static inline void hisi_thermal_sensor_select(void __iomem *addr, int sensor)
>> +static inline int hisi_thermal_get_temperature(void __iomem *addr)
>>  {
>> -	writel((sensor << 12), addr + TEMP0_CFG);
>> +	return hisi_thermal_step_to_temp(readl(addr + TEMP0_VALUE));
>>  }
>>  
>> -static inline int hisi_thermal_get_temperature(void __iomem *addr)
>> +/*
>> + * Temperature configuration register - Sensor selection
>> + *
>> + * Bits [19:12]
>> + *
>> + * 0x0: local sensor (default)
>> + * 0x1: remote sensor 1 (ACPU cluster 1)
>> + * 0x2: remote sensor 2 (ACPU cluster 0)
>> + * 0x3: remote sensor 3 (G3D)
>> + */
>> +static inline void hisi_thermal_sensor_select(void __iomem *addr, int sensor)
>>  {
>> -	return hisi_thermal_step_to_temp(readl(addr + TEMP0_VALUE));
>> +	writel(readl(addr + TEMP0_CFG) | (sensor << 12), addr + TEMP0_CFG);
> 
> nitpick: maybe it's better to firstly clear related bits and then set
> value?

Sorry, I don't get the comment. Can you elaborate ?


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#1725793 — Re: [PATCH 08/13] thermal/drivers/hisi: Fix configuration register setting

On Sat, Sep 02, 2017 at 10:34:34AM +0200, Daniel Lezcano wrote:
> On 02/09/2017 04:54, Leo Yan wrote:
> > On Wed, Aug 30, 2017 at 10:47:32AM +0200, Daniel Lezcano wrote:
> >> The TEMP0_CFG configuration register contains different field to set up the
> >> temperature controller. However in the code, nothing prevents a setup to
> >> overwrite the previous one: eg. writing the hdak value overwrites the sensor
> >> selection, the sensor selection overwrites the hdak value.
> >>
> >> In order to prevent such thing, use a regmap-like mechanism by reading the
> >> value before, set the corresponding bits and write the result.
> >>
> >> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> >> ---
> >>  drivers/thermal/hisi_thermal.c | 30 +++++++++++++++++++++++++-----
> >>  1 file changed, 25 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
> >> index d77a938..3e03908 100644
> >> --- a/drivers/thermal/hisi_thermal.c
> >> +++ b/drivers/thermal/hisi_thermal.c
> >> @@ -132,19 +132,39 @@ static inline void hisi_thermal_enable(void __iomem *addr, int value)
> >>  	writel(value, addr + TEMP0_EN);
> >>  }
> >>  
> >> -static inline void hisi_thermal_sensor_select(void __iomem *addr, int sensor)
> >> +static inline int hisi_thermal_get_temperature(void __iomem *addr)
> >>  {
> >> -	writel((sensor << 12), addr + TEMP0_CFG);
> >> +	return hisi_thermal_step_to_temp(readl(addr + TEMP0_VALUE));
> >>  }
> >>  
> >> -static inline int hisi_thermal_get_temperature(void __iomem *addr)
> >> +/*
> >> + * Temperature configuration register - Sensor selection
> >> + *
> >> + * Bits [19:12]
> >> + *
> >> + * 0x0: local sensor (default)
> >> + * 0x1: remote sensor 1 (ACPU cluster 1)
> >> + * 0x2: remote sensor 2 (ACPU cluster 0)
> >> + * 0x3: remote sensor 3 (G3D)
> >> + */
> >> +static inline void hisi_thermal_sensor_select(void __iomem *addr, int sensor)
> >>  {
> >> -	return hisi_thermal_step_to_temp(readl(addr + TEMP0_VALUE));
> >> +	writel(readl(addr + TEMP0_CFG) | (sensor << 12), addr + TEMP0_CFG);
> > 
> > nitpick: maybe it's better to firstly clear related bits and then set
> > value?
> 
> Sorry, I don't get the comment. Can you elaborate ?

Sure, here I am bit concern there the mixing old bits value and new
setting bits. My suggested code likes below:

  u32 val;

  val = readl(addr + TEMP0_CFG);
  val &= ~0xF000;
  val |= (sensor << 12);
  writel(val, addr + TEMP0_CFG);

Thanks,
Leo Yan

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#1725960 — Re: [PATCH 08/13] thermal/drivers/hisi: Fix configuration register setting

On 04/09/2017 02:58, Leo Yan wrote:
> On Sat, Sep 02, 2017 at 10:34:34AM +0200, Daniel Lezcano wrote:
>> On 02/09/2017 04:54, Leo Yan wrote:
>>> On Wed, Aug 30, 2017 at 10:47:32AM +0200, Daniel Lezcano wrote:
>>>> The TEMP0_CFG configuration register contains different field to set up the
>>>> temperature controller. However in the code, nothing prevents a setup to
>>>> overwrite the previous one: eg. writing the hdak value overwrites the sensor
>>>> selection, the sensor selection overwrites the hdak value.
>>>>
>>>> In order to prevent such thing, use a regmap-like mechanism by reading the
>>>> value before, set the corresponding bits and write the result.
>>>>
>>>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
>>>> ---
>>>>  drivers/thermal/hisi_thermal.c | 30 +++++++++++++++++++++++++-----
>>>>  1 file changed, 25 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
>>>> index d77a938..3e03908 100644
>>>> --- a/drivers/thermal/hisi_thermal.c
>>>> +++ b/drivers/thermal/hisi_thermal.c
>>>> @@ -132,19 +132,39 @@ static inline void hisi_thermal_enable(void __iomem *addr, int value)
>>>>  	writel(value, addr + TEMP0_EN);
>>>>  }
>>>>  
>>>> -static inline void hisi_thermal_sensor_select(void __iomem *addr, int sensor)
>>>> +static inline int hisi_thermal_get_temperature(void __iomem *addr)
>>>>  {
>>>> -	writel((sensor << 12), addr + TEMP0_CFG);
>>>> +	return hisi_thermal_step_to_temp(readl(addr + TEMP0_VALUE));
>>>>  }
>>>>  
>>>> -static inline int hisi_thermal_get_temperature(void __iomem *addr)
>>>> +/*
>>>> + * Temperature configuration register - Sensor selection
>>>> + *
>>>> + * Bits [19:12]
>>>> + *
>>>> + * 0x0: local sensor (default)
>>>> + * 0x1: remote sensor 1 (ACPU cluster 1)
>>>> + * 0x2: remote sensor 2 (ACPU cluster 0)
>>>> + * 0x3: remote sensor 3 (G3D)
>>>> + */
>>>> +static inline void hisi_thermal_sensor_select(void __iomem *addr, int sensor)
>>>>  {
>>>> -	return hisi_thermal_step_to_temp(readl(addr + TEMP0_VALUE));
>>>> +	writel(readl(addr + TEMP0_CFG) | (sensor << 12), addr + TEMP0_CFG);
>>>
>>> nitpick: maybe it's better to firstly clear related bits and then set
>>> value?
>>
>> Sorry, I don't get the comment. Can you elaborate ?
> 
> Sure, here I am bit concern there the mixing old bits value and new
> setting bits. My suggested code likes below:
> 
>   u32 val;
> 
>   val = readl(addr + TEMP0_CFG);
>   val &= ~0xF000;
>   val |= (sensor << 12);
>   writel(val, addr + TEMP0_CFG);

Oh, yes. Good catch.


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#1723132 — [PATCH 09/13] thermal/drivers/hisi: Remove costly sensor inspection

The sensor is all setup, bind, resetted, acked, etc... every single second.

That was the way to workaround a problem with the interrupt bouncing again and
again.

With the following changes, we fix all in one:

 - Do the setup, one time, at probe time

 - Add the IRQF_ONESHOT, ack the interrupt in the threaded handler

 - Remove the interrupt handler

 - Set the correct value for the LAG register

 - Remove all the irq_enabled stuff in the code as the interruption
   handling is fixed

 - Remove the 3ms delay

 - Reorder the initialization routine to be in the right order

It ends up to a nicer code and more efficient, the 3-5ms delay is removed from
the get_temp() path.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/thermal/hisi_thermal.c | 203 +++++++++++++++++++----------------------
 1 file changed, 93 insertions(+), 110 deletions(-)

diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
index 3e03908..b038d8a 100644
--- a/drivers/thermal/hisi_thermal.c
+++ b/drivers/thermal/hisi_thermal.c
@@ -39,6 +39,7 @@
 #define HISI_TEMP_BASE			(-60000)
 #define HISI_TEMP_RESET			(100000)
 #define HISI_TEMP_STEP			(784)
+#define HISI_TEMP_LAG			(3500)
 
 #define HISI_MAX_SENSORS		4
 #define HISI_DEFAULT_SENSOR		2
@@ -58,8 +59,6 @@ struct hisi_thermal_data {
 	struct clk *clk;
 	struct hisi_thermal_sensor sensors;
 	int irq;
-	bool irq_enabled;
-	
 	void __iomem *regs;
 };
 
@@ -97,9 +96,40 @@ static inline long hisi_thermal_round_temp(int temp)
 		hisi_thermal_temp_to_step(temp));
 }
 
+/*
+ * The lag register contains 5 bits encoding the temperature in steps.
+ *
+ * Each time the temperature crosses the threshold boundary, an
+ * interrupt is raised. It could be when the temperature is going
+ * above the threshold or below. However, if the temperature is
+ * fluctuating around this value due to the load, we can receive
+ * several interrupts which may not desired.
+ *
+ * We can setup a temperature representing the delta between the
+ * threshold and the current temperature when the temperature is
+ * decreasing.
+ *
+ * For instance: the lag register is 5°C, the threshold is 65°C, when
+ * the temperature reaches 65°C an interrupt is raised and when the
+ * temperature decrease to 65°C - 5°C another interrupt is raised.
+ *
+ * A very short lag can lead to an interrupt storm, a long lag
+ * increase the latency to react to the temperature changes.  In our
+ * case, that is not really a problem as we are polling the
+ * temperature.
+ *
+ * [0:4] : lag register
+ *
+ * The temperature is coded in steps, cf. HISI_TEMP_STEP.
+ *
+ * Min : 0x00 :  0.0 °C
+ * Max : 0x1F : 24.3 °C
+ *
+ * The 'value' parameter is in milliCelsius.
+ */
 static inline void hisi_thermal_set_lag(void __iomem *addr, int value)
 {
-	writel(value, addr + TEMP0_LAG);
+	writel((value / HISI_TEMP_STEP) & 0x1F, addr + TEMP0_LAG);
 }
 
 static inline void hisi_thermal_alarm_clear(void __iomem *addr, int value)
@@ -167,71 +197,6 @@ static inline void hisi_thermal_hdak_set(void __iomem *addr, int value)
 	writel(readl(addr + TEMP0_CFG) | (value << 4), addr + TEMP0_CFG);
 }
 
-static long hisi_thermal_get_sensor_temp(struct hisi_thermal_data *data,
-					 struct hisi_thermal_sensor *sensor)
-{
-	long val;
-
-	mutex_lock(&data->thermal_lock);
-
-	/* disable interrupt */
-	hisi_thermal_alarm_enable(data->regs, 0);
-	hisi_thermal_alarm_clear(data->regs, 1);
-
-	/* disable module firstly */
-	hisi_thermal_enable(data->regs, 0);
-
-	/* select sensor id */
-	hisi_thermal_sensor_select(data->regs, sensor->id);
-
-	/* enable module */
-	hisi_thermal_enable(data->regs, 1);
-
-	usleep_range(3000, 5000);
-
-	val = hisi_thermal_get_temperature(data->regs);
-
-	mutex_unlock(&data->thermal_lock);
-
-	return val;
-}
-
-static void hisi_thermal_enable_bind_irq_sensor
-			(struct hisi_thermal_data *data)
-{
-	struct hisi_thermal_sensor *sensor;
-
-	mutex_lock(&data->thermal_lock);
-
-	sensor = &data->sensors;
-
-	/* setting the hdak time */
-	hisi_thermal_hdak_set(data->regs, 0);
-
-	/* disable module firstly */
-	hisi_thermal_reset_enable(data->regs, 0);
-	hisi_thermal_enable(data->regs, 0);
-
-	/* select sensor id */
-	hisi_thermal_sensor_select(data->regs, sensor->id);
-
-	/* enable for interrupt */
-	hisi_thermal_alarm_set(data->regs, sensor->thres_temp);
-
-	hisi_thermal_reset_set(data->regs, HISI_TEMP_RESET);
-
-	/* enable module */
-	hisi_thermal_reset_enable(data->regs, 1);
-	hisi_thermal_enable(data->regs, 1);
-
-	hisi_thermal_alarm_clear(data->regs, 0);
-	hisi_thermal_alarm_enable(data->regs, 1);
-	
-	usleep_range(3000, 5000);
-
-	mutex_unlock(&data->thermal_lock);
-}
-
 static void hisi_thermal_disable_sensor(struct hisi_thermal_data *data)
 {
 	mutex_lock(&data->thermal_lock);
@@ -249,25 +214,10 @@ static int hisi_thermal_get_temp(void *_sensor, int *temp)
 	struct hisi_thermal_sensor *sensor = _sensor;
 	struct hisi_thermal_data *data = sensor->thermal;
 
-	*temp = hisi_thermal_get_sensor_temp(data, sensor);
-
-	dev_dbg(&data->pdev->dev, "id=%d, irq=%d, temp=%d, thres=%d\n",
-		sensor->id, data->irq_enabled, *temp, sensor->thres_temp);
-	/*
-	 * Bind irq to sensor for two cases:
-	 *   Reenable alarm IRQ if temperature below threshold;
-	 *   if irq has been enabled, always set it;
-	 */
-	if (data->irq_enabled) {
-		hisi_thermal_enable_bind_irq_sensor(data);
-		return 0;
-	}
+	*temp = hisi_thermal_get_temperature(data->regs);
 
-	if (*temp < sensor->thres_temp) {
-		data->irq_enabled = true;
-		hisi_thermal_enable_bind_irq_sensor(data);
-		enable_irq(data->irq);
-	}
+	dev_dbg(&data->pdev->dev, "id=%d, temp=%d, thres=%d\n",
+		sensor->id, *temp, sensor->thres_temp);
 
 	return 0;
 }
@@ -276,26 +226,27 @@ static const struct thermal_zone_of_device_ops hisi_of_thermal_ops = {
 	.get_temp = hisi_thermal_get_temp,
 };
 
-static irqreturn_t hisi_thermal_alarm_irq(int irq, void *dev)
+static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
 {
 	struct hisi_thermal_data *data = dev;
+	struct hisi_thermal_sensor *sensor = &data->sensors;
+	int temp;
 
-	disable_irq_nosync(irq);
-	data->irq_enabled = false;
+	hisi_thermal_alarm_clear(data->regs, 1);
 
-	return IRQ_WAKE_THREAD;
-}
+	temp = hisi_thermal_get_temperature(data->regs);
 
-static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
-{
-	struct hisi_thermal_data *data = dev;
-	struct hisi_thermal_sensor *sensor = &data->sensors;
+	if (temp >= sensor->thres_temp) {
+		dev_crit(&data->pdev->dev, "THERMAL ALARM: %d > %d\n",
+			 temp, sensor->thres_temp);
 
-	dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",
-		 sensor->thres_temp);
+		thermal_zone_device_update(data->sensors.tzd,
+					   THERMAL_EVENT_UNSPECIFIED);
 
-	thermal_zone_device_update(data->sensors.tzd,
-				   THERMAL_EVENT_UNSPECIFIED);
+	} else if (temp < sensor->thres_temp) {
+		dev_crit(&data->pdev->dev, "THERMAL ALARM stopped: %d < %d\n",
+			 temp, sensor->thres_temp);
+	}
 
 	return IRQ_HANDLED;
 }
@@ -348,6 +299,40 @@ static void hisi_thermal_toggle_sensor(struct hisi_thermal_sensor *sensor,
 		on ? THERMAL_DEVICE_ENABLED : THERMAL_DEVICE_DISABLED);
 }
 
+static int hisi_thermal_setup(struct hisi_thermal_data *data)
+{
+	struct hisi_thermal_sensor *sensor;
+
+	sensor = &data->sensors;
+
+	/* disable module firstly */
+	hisi_thermal_reset_enable(data->regs, 0);
+	hisi_thermal_enable(data->regs, 0);
+
+	/* select sensor id */
+	hisi_thermal_sensor_select(data->regs, sensor->id);
+
+	/* setting the hdak time */
+	hisi_thermal_hdak_set(data->regs, 0);
+
+	/* setting lag value between current temp and the threshold */
+	hisi_thermal_set_lag(data->regs, HISI_TEMP_LAG);
+
+	/* enable for interrupt */
+	hisi_thermal_alarm_set(data->regs, sensor->thres_temp);
+
+	hisi_thermal_reset_set(data->regs, HISI_TEMP_RESET);
+
+	/* enable module */
+	hisi_thermal_reset_enable(data->regs, 1);
+	hisi_thermal_enable(data->regs, 1);
+
+	hisi_thermal_alarm_clear(data->regs, 0);
+	hisi_thermal_alarm_enable(data->regs, 1);
+
+	return 0;
+}
+
 static int hisi_thermal_probe(struct platform_device *pdev)
 {
 	struct hisi_thermal_data *data;
@@ -390,9 +375,6 @@ static int hisi_thermal_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	hisi_thermal_enable_bind_irq_sensor(data);
-	data->irq_enabled = true;
-
 	ret = hisi_thermal_register_sensor(pdev, data,
 					   &data->sensors,
 					   HISI_DEFAULT_SENSOR);
@@ -402,18 +384,21 @@ static int hisi_thermal_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	hisi_thermal_toggle_sensor(&data->sensors, true);
+	ret = hisi_thermal_setup(data);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to setup the sensor: %d\n", ret);
+		return ret;
+	}
 
-	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
-					hisi_thermal_alarm_irq,
+	ret = devm_request_threaded_irq(&pdev->dev, data->irq, NULL,
 					hisi_thermal_alarm_irq_thread,
-					0, "hisi_thermal", data);
+					IRQF_ONESHOT, "hisi_thermal", data);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
 		return ret;
 	}
 
-	enable_irq(data->irq);
+	hisi_thermal_toggle_sensor(&data->sensors, true);
 
 	return 0;
 }
@@ -436,7 +421,6 @@ static int hisi_thermal_suspend(struct device *dev)
 	struct hisi_thermal_data *data = dev_get_drvdata(dev);
 
 	hisi_thermal_disable_sensor(data);
-	data->irq_enabled = false;
 
 	clk_disable_unprepare(data->clk);
 
@@ -452,8 +436,7 @@ static int hisi_thermal_resume(struct device *dev)
 	if (ret)
 		return ret;
 
-	data->irq_enabled = true;
-	hisi_thermal_enable_bind_irq_sensor(data);
+	hisi_thermal_setup(data);
 
 	return 0;
 }
-- 
2.7.4

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#1725430 — Re: [PATCH 09/13] thermal/drivers/hisi: Remove costly sensor inspection

On Wed, Aug 30, 2017 at 10:47:33AM +0200, Daniel Lezcano wrote:
> The sensor is all setup, bind, resetted, acked, etc... every single second.
> 
> That was the way to workaround a problem with the interrupt bouncing again and
> again.
> 
> With the following changes, we fix all in one:
> 
>  - Do the setup, one time, at probe time
> 
>  - Add the IRQF_ONESHOT, ack the interrupt in the threaded handler
> 
>  - Remove the interrupt handler
> 
>  - Set the correct value for the LAG register
> 
>  - Remove all the irq_enabled stuff in the code as the interruption
>    handling is fixed
> 
>  - Remove the 3ms delay
> 
>  - Reorder the initialization routine to be in the right order
> 
> It ends up to a nicer code and more efficient, the 3-5ms delay is removed from
> the get_temp() path.
> 
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---
>  drivers/thermal/hisi_thermal.c | 203 +++++++++++++++++++----------------------
>  1 file changed, 93 insertions(+), 110 deletions(-)
> 
> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
> index 3e03908..b038d8a 100644
> --- a/drivers/thermal/hisi_thermal.c
> +++ b/drivers/thermal/hisi_thermal.c
> @@ -39,6 +39,7 @@
>  #define HISI_TEMP_BASE			(-60000)
>  #define HISI_TEMP_RESET			(100000)
>  #define HISI_TEMP_STEP			(784)
> +#define HISI_TEMP_LAG			(3500)

So I am curious what's the reason to select 3.5'c for lag value? Is
this a heuristics result?

>  #define HISI_MAX_SENSORS		4
>  #define HISI_DEFAULT_SENSOR		2
> @@ -58,8 +59,6 @@ struct hisi_thermal_data {
>  	struct clk *clk;
>  	struct hisi_thermal_sensor sensors;
>  	int irq;
> -	bool irq_enabled;
> -	
>  	void __iomem *regs;
>  };
>  
> @@ -97,9 +96,40 @@ static inline long hisi_thermal_round_temp(int temp)
>  		hisi_thermal_temp_to_step(temp));
>  }
>  
> +/*
> + * The lag register contains 5 bits encoding the temperature in steps.
> + *
> + * Each time the temperature crosses the threshold boundary, an
> + * interrupt is raised. It could be when the temperature is going
> + * above the threshold or below. However, if the temperature is
> + * fluctuating around this value due to the load, we can receive
> + * several interrupts which may not desired.
> + *
> + * We can setup a temperature representing the delta between the
> + * threshold and the current temperature when the temperature is
> + * decreasing.
> + *
> + * For instance: the lag register is 5°C, the threshold is 65°C, when
> + * the temperature reaches 65°C an interrupt is raised and when the
> + * temperature decrease to 65°C - 5°C another interrupt is raised.
> + *
> + * A very short lag can lead to an interrupt storm, a long lag
> + * increase the latency to react to the temperature changes.  In our
> + * case, that is not really a problem as we are polling the
> + * temperature.

So here means if we set a long lag value and the interrupt is delayed,
sometimes we even don't receive the interrupt; but this is acceptable
due we are polling the temperature so we still can get the updated
temperature value, right?

> + *
> + * [0:4] : lag register
> + *
> + * The temperature is coded in steps, cf. HISI_TEMP_STEP.
> + *
> + * Min : 0x00 :  0.0 °C
> + * Max : 0x1F : 24.3 °C
> + *
> + * The 'value' parameter is in milliCelsius.
> + */
>  static inline void hisi_thermal_set_lag(void __iomem *addr, int value)
>  {
> -	writel(value, addr + TEMP0_LAG);
> +	writel((value / HISI_TEMP_STEP) & 0x1F, addr + TEMP0_LAG);
>  }
>  
>  static inline void hisi_thermal_alarm_clear(void __iomem *addr, int value)
> @@ -167,71 +197,6 @@ static inline void hisi_thermal_hdak_set(void __iomem *addr, int value)
>  	writel(readl(addr + TEMP0_CFG) | (value << 4), addr + TEMP0_CFG);
>  }
>  
> -static long hisi_thermal_get_sensor_temp(struct hisi_thermal_data *data,
> -					 struct hisi_thermal_sensor *sensor)
> -{
> -	long val;
> -
> -	mutex_lock(&data->thermal_lock);
> -
> -	/* disable interrupt */
> -	hisi_thermal_alarm_enable(data->regs, 0);
> -	hisi_thermal_alarm_clear(data->regs, 1);
> -
> -	/* disable module firstly */
> -	hisi_thermal_enable(data->regs, 0);
> -
> -	/* select sensor id */
> -	hisi_thermal_sensor_select(data->regs, sensor->id);
> -
> -	/* enable module */
> -	hisi_thermal_enable(data->regs, 1);
> -
> -	usleep_range(3000, 5000);
> -
> -	val = hisi_thermal_get_temperature(data->regs);
> -
> -	mutex_unlock(&data->thermal_lock);
> -
> -	return val;
> -}
> -
> -static void hisi_thermal_enable_bind_irq_sensor
> -			(struct hisi_thermal_data *data)
> -{
> -	struct hisi_thermal_sensor *sensor;
> -
> -	mutex_lock(&data->thermal_lock);
> -
> -	sensor = &data->sensors;
> -
> -	/* setting the hdak time */
> -	hisi_thermal_hdak_set(data->regs, 0);
> -
> -	/* disable module firstly */
> -	hisi_thermal_reset_enable(data->regs, 0);
> -	hisi_thermal_enable(data->regs, 0);
> -
> -	/* select sensor id */
> -	hisi_thermal_sensor_select(data->regs, sensor->id);
> -
> -	/* enable for interrupt */
> -	hisi_thermal_alarm_set(data->regs, sensor->thres_temp);
> -
> -	hisi_thermal_reset_set(data->regs, HISI_TEMP_RESET);
> -
> -	/* enable module */
> -	hisi_thermal_reset_enable(data->regs, 1);
> -	hisi_thermal_enable(data->regs, 1);
> -
> -	hisi_thermal_alarm_clear(data->regs, 0);
> -	hisi_thermal_alarm_enable(data->regs, 1);
> -	
> -	usleep_range(3000, 5000);
> -
> -	mutex_unlock(&data->thermal_lock);
> -}
> -
>  static void hisi_thermal_disable_sensor(struct hisi_thermal_data *data)
>  {
>  	mutex_lock(&data->thermal_lock);
> @@ -249,25 +214,10 @@ static int hisi_thermal_get_temp(void *_sensor, int *temp)
>  	struct hisi_thermal_sensor *sensor = _sensor;
>  	struct hisi_thermal_data *data = sensor->thermal;
>  
> -	*temp = hisi_thermal_get_sensor_temp(data, sensor);
> -
> -	dev_dbg(&data->pdev->dev, "id=%d, irq=%d, temp=%d, thres=%d\n",
> -		sensor->id, data->irq_enabled, *temp, sensor->thres_temp);
> -	/*
> -	 * Bind irq to sensor for two cases:
> -	 *   Reenable alarm IRQ if temperature below threshold;
> -	 *   if irq has been enabled, always set it;
> -	 */
> -	if (data->irq_enabled) {
> -		hisi_thermal_enable_bind_irq_sensor(data);
> -		return 0;
> -	}
> +	*temp = hisi_thermal_get_temperature(data->regs);
>  
> -	if (*temp < sensor->thres_temp) {
> -		data->irq_enabled = true;
> -		hisi_thermal_enable_bind_irq_sensor(data);
> -		enable_irq(data->irq);
> -	}
> +	dev_dbg(&data->pdev->dev, "id=%d, temp=%d, thres=%d\n",
> +		sensor->id, *temp, sensor->thres_temp);
>  
>  	return 0;
>  }
> @@ -276,26 +226,27 @@ static const struct thermal_zone_of_device_ops hisi_of_thermal_ops = {
>  	.get_temp = hisi_thermal_get_temp,
>  };
>  
> -static irqreturn_t hisi_thermal_alarm_irq(int irq, void *dev)
> +static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
>  {
>  	struct hisi_thermal_data *data = dev;
> +	struct hisi_thermal_sensor *sensor = &data->sensors;
> +	int temp;
>  
> -	disable_irq_nosync(irq);
> -	data->irq_enabled = false;
> +	hisi_thermal_alarm_clear(data->regs, 1);
>  
> -	return IRQ_WAKE_THREAD;
> -}
> +	temp = hisi_thermal_get_temperature(data->regs);
>  
> -static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
> -{
> -	struct hisi_thermal_data *data = dev;
> -	struct hisi_thermal_sensor *sensor = &data->sensors;
> +	if (temp >= sensor->thres_temp) {
> +		dev_crit(&data->pdev->dev, "THERMAL ALARM: %d > %d\n",
> +			 temp, sensor->thres_temp);
>  
> -	dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",
> -		 sensor->thres_temp);
> +		thermal_zone_device_update(data->sensors.tzd,
> +					   THERMAL_EVENT_UNSPECIFIED);
>  
> -	thermal_zone_device_update(data->sensors.tzd,
> -				   THERMAL_EVENT_UNSPECIFIED);
> +	} else if (temp < sensor->thres_temp) {
> +		dev_crit(&data->pdev->dev, "THERMAL ALARM stopped: %d < %d\n",
> +			 temp, sensor->thres_temp);
> +	}

For temperature increasing and decreasing both cases, can always call
thermal_zone_device_update()?

>  
>  	return IRQ_HANDLED;
>  }
> @@ -348,6 +299,40 @@ static void hisi_thermal_toggle_sensor(struct hisi_thermal_sensor *sensor,
>  		on ? THERMAL_DEVICE_ENABLED : THERMAL_DEVICE_DISABLED);
>  }
>  
> +static int hisi_thermal_setup(struct hisi_thermal_data *data)
> +{
> +	struct hisi_thermal_sensor *sensor;
> +
> +	sensor = &data->sensors;
> +
> +	/* disable module firstly */
> +	hisi_thermal_reset_enable(data->regs, 0);
> +	hisi_thermal_enable(data->regs, 0);
> +
> +	/* select sensor id */
> +	hisi_thermal_sensor_select(data->regs, sensor->id);
> +
> +	/* setting the hdak time */
> +	hisi_thermal_hdak_set(data->regs, 0);
> +
> +	/* setting lag value between current temp and the threshold */
> +	hisi_thermal_set_lag(data->regs, HISI_TEMP_LAG);
> +
> +	/* enable for interrupt */
> +	hisi_thermal_alarm_set(data->regs, sensor->thres_temp);
> +
> +	hisi_thermal_reset_set(data->regs, HISI_TEMP_RESET);
> +
> +	/* enable module */
> +	hisi_thermal_reset_enable(data->regs, 1);
> +	hisi_thermal_enable(data->regs, 1);
> +
> +	hisi_thermal_alarm_clear(data->regs, 0);
> +	hisi_thermal_alarm_enable(data->regs, 1);
> +
> +	return 0;
> +}
> +
>  static int hisi_thermal_probe(struct platform_device *pdev)
>  {
>  	struct hisi_thermal_data *data;
> @@ -390,9 +375,6 @@ static int hisi_thermal_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> -	hisi_thermal_enable_bind_irq_sensor(data);
> -	data->irq_enabled = true;
> -
>  	ret = hisi_thermal_register_sensor(pdev, data,
>  					   &data->sensors,
>  					   HISI_DEFAULT_SENSOR);
> @@ -402,18 +384,21 @@ static int hisi_thermal_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> -	hisi_thermal_toggle_sensor(&data->sensors, true);
> +	ret = hisi_thermal_setup(data);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to setup the sensor: %d\n", ret);
> +		return ret;
> +	}
>  
> -	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
> -					hisi_thermal_alarm_irq,
> +	ret = devm_request_threaded_irq(&pdev->dev, data->irq, NULL,
>  					hisi_thermal_alarm_irq_thread,
> -					0, "hisi_thermal", data);
> +					IRQF_ONESHOT, "hisi_thermal", data);
>  	if (ret < 0) {
>  		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
>  		return ret;
>  	}
>  
> -	enable_irq(data->irq);
> +	hisi_thermal_toggle_sensor(&data->sensors, true);
>  
>  	return 0;
>  }
> @@ -436,7 +421,6 @@ static int hisi_thermal_suspend(struct device *dev)
>  	struct hisi_thermal_data *data = dev_get_drvdata(dev);
>  
>  	hisi_thermal_disable_sensor(data);
> -	data->irq_enabled = false;
>  
>  	clk_disable_unprepare(data->clk);
>  
> @@ -452,8 +436,7 @@ static int hisi_thermal_resume(struct device *dev)
>  	if (ret)
>  		return ret;
>  
> -	data->irq_enabled = true;
> -	hisi_thermal_enable_bind_irq_sensor(data);
> +	hisi_thermal_setup(data);
>  
>  	return 0;
>  }
> -- 
> 2.7.4
> 

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#1725504 — Re: [PATCH 09/13] thermal/drivers/hisi: Remove costly sensor inspection

On 02/09/2017 05:29, Leo Yan wrote:
> On Wed, Aug 30, 2017 at 10:47:33AM +0200, Daniel Lezcano wrote:
>> The sensor is all setup, bind, resetted, acked, etc... every single second.
>>
>> That was the way to workaround a problem with the interrupt bouncing again and
>> again.
>>
>> With the following changes, we fix all in one:
>>
>>  - Do the setup, one time, at probe time
>>
>>  - Add the IRQF_ONESHOT, ack the interrupt in the threaded handler
>>
>>  - Remove the interrupt handler
>>
>>  - Set the correct value for the LAG register
>>
>>  - Remove all the irq_enabled stuff in the code as the interruption
>>    handling is fixed
>>
>>  - Remove the 3ms delay
>>
>>  - Reorder the initialization routine to be in the right order
>>
>> It ends up to a nicer code and more efficient, the 3-5ms delay is removed from
>> the get_temp() path.
>>
>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
>> ---
>>  drivers/thermal/hisi_thermal.c | 203 +++++++++++++++++++----------------------
>>  1 file changed, 93 insertions(+), 110 deletions(-)
>>
>> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
>> index 3e03908..b038d8a 100644
>> --- a/drivers/thermal/hisi_thermal.c
>> +++ b/drivers/thermal/hisi_thermal.c
>> @@ -39,6 +39,7 @@
>>  #define HISI_TEMP_BASE			(-60000)
>>  #define HISI_TEMP_RESET			(100000)
>>  #define HISI_TEMP_STEP			(784)
>> +#define HISI_TEMP_LAG			(3500)
> 
> So I am curious what's the reason to select 3.5'c for lag value? Is
> this a heuristics result?

Yes, it is. I tried 5°C but I find it too long. After several tests, I
found 3.5°C looked fine.

[ ... ]

>> + * A very short lag can lead to an interrupt storm, a long lag
>> + * increase the latency to react to the temperature changes.  In our
>> + * case, that is not really a problem as we are polling the
>> + * temperature.
> 
> So here means if we set a long lag value and the interrupt is delayed,
> sometimes we even don't receive the interrupt; but this is acceptable
> due we are polling the temperature so we still can get the updated
> temperature value, right?
No, what I meant is if the hysteresis is too large, eg. 45 - 65, then
the interrupt will come after the temperature goes below 45 and that may
take a long time, especially if the temperature is fluctuating between
the two hysteresis values.

The only setup preventing an interrupt to happen is when crossing the
low value hysteresis is not possible in practical. For example, the
temperature of the SoC is ~44°C at idle time. If we set the threshold to
65°C and the lag to the max 24°C, the interrupt will raised when we go
below 41°C and that situation can't happen.

In the current situation, the interrupt is only used to raise an alarm.
The get temperature is resulting from a polling, so the delay between
the alarm on/off is not issue for now.

>> + *
>> + * [0:4] : lag register
>> + *
>> + * The temperature is coded in steps, cf. HISI_TEMP_STEP.
>> + *
>> + * Min : 0x00 :  0.0 °C
>> + * Max : 0x1F : 24.3 °C
>> + *
>> + * The 'value' parameter is in milliCelsius.
>> + */
>>  static inline void hisi_thermal_set_lag(void __iomem *addr, int value)
>>  {
>> -	writel(value, addr + TEMP0_LAG);
>> +	writel((value / HISI_TEMP_STEP) & 0x1F, addr + TEMP0_LAG);
>>  }


[ ... ]

>> -	thermal_zone_device_update(data->sensors.tzd,
>> -				   THERMAL_EVENT_UNSPECIFIED);
>> +	} else if (temp < sensor->thres_temp) {
>> +		dev_crit(&data->pdev->dev, "THERMAL ALARM stopped: %d < %d\n",
>> +			 temp, sensor->thres_temp);
>> +	}
> 
> For temperature increasing and decreasing both cases, can always call
> thermal_zone_device_update()?

That is something I asked myself but I finally decided to not change the
current behavior and let that be added in a separate patch.


[ ... ]



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#1725794 — Re: [PATCH 09/13] thermal/drivers/hisi: Remove costly sensor inspection

On Sat, Sep 02, 2017 at 03:10:29PM +0200, Daniel Lezcano wrote:

[...]

> On 02/09/2017 05:29, Leo Yan wrote:
> > On Wed, Aug 30, 2017 at 10:47:33AM +0200, Daniel Lezcano wrote:
> >> The sensor is all setup, bind, resetted, acked, etc... every single second.
> >>
> >> That was the way to workaround a problem with the interrupt bouncing again and
> >> again.
> >>
> >> With the following changes, we fix all in one:
> >>
> >>  - Do the setup, one time, at probe time
> >>
> >>  - Add the IRQF_ONESHOT, ack the interrupt in the threaded handler
> >>
> >>  - Remove the interrupt handler
> >>
> >>  - Set the correct value for the LAG register
> >>
> >>  - Remove all the irq_enabled stuff in the code as the interruption
> >>    handling is fixed
> >>
> >>  - Remove the 3ms delay
> >>
> >>  - Reorder the initialization routine to be in the right order
> >>
> >> It ends up to a nicer code and more efficient, the 3-5ms delay is removed from
> >> the get_temp() path.
> >>
> >> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> >> ---
> >>  drivers/thermal/hisi_thermal.c | 203 +++++++++++++++++++----------------------
> >>  1 file changed, 93 insertions(+), 110 deletions(-)
> >>
> >> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
> >> index 3e03908..b038d8a 100644
> >> --- a/drivers/thermal/hisi_thermal.c
> >> +++ b/drivers/thermal/hisi_thermal.c
> >> @@ -39,6 +39,7 @@
> >>  #define HISI_TEMP_BASE			(-60000)
> >>  #define HISI_TEMP_RESET			(100000)
> >>  #define HISI_TEMP_STEP			(784)
> >> +#define HISI_TEMP_LAG			(3500)
> > 
> > So I am curious what's the reason to select 3.5'c for lag value? Is
> > this a heuristics result?
> 
> Yes, it is. I tried 5°C but I find it too long. After several tests, I
> found 3.5°C looked fine.
> 
> [ ... ]
> 
> >> + * A very short lag can lead to an interrupt storm, a long lag
> >> + * increase the latency to react to the temperature changes.  In our
> >> + * case, that is not really a problem as we are polling the
> >> + * temperature.
> > 
> > So here means if we set a long lag value and the interrupt is delayed,
> > sometimes we even don't receive the interrupt; but this is acceptable
> > due we are polling the temperature so we still can get the updated
> > temperature value, right?
> No, what I meant is if the hysteresis is too large, eg. 45 - 65, then
> the interrupt will come after the temperature goes below 45 and that may
> take a long time, especially if the temperature is fluctuating between
> the two hysteresis values.
> 
> The only setup preventing an interrupt to happen is when crossing the
> low value hysteresis is not possible in practical. For example, the
> temperature of the SoC is ~44°C at idle time. If we set the threshold to
> 65°C and the lag to the max 24°C, the interrupt will raised when we go
> below 41°C and that situation can't happen.
> 
> In the current situation, the interrupt is only used to raise an alarm.

Thanks for the explanation, Ionela (have Cced.) reminded me the
interrupt for 'alarm on' is fatal, if we use polling method then the
delay can be 1000ms, but with interrupt to alarm we can handle the
temperature rasing immediately.

> The get temperature is resulting from a polling, so the delay between
> the alarm on/off is not issue for now.

Understood.

> >> + *
> >> + * [0:4] : lag register
> >> + *
> >> + * The temperature is coded in steps, cf. HISI_TEMP_STEP.
> >> + *
> >> + * Min : 0x00 :  0.0 °C
> >> + * Max : 0x1F : 24.3 °C
> >> + *
> >> + * The 'value' parameter is in milliCelsius.
> >> + */
> >>  static inline void hisi_thermal_set_lag(void __iomem *addr, int value)
> >>  {
> >> -	writel(value, addr + TEMP0_LAG);
> >> +	writel((value / HISI_TEMP_STEP) & 0x1F, addr + TEMP0_LAG);
> >>  }
> 
> 
> [ ... ]
> 
> >> -	thermal_zone_device_update(data->sensors.tzd,
> >> -				   THERMAL_EVENT_UNSPECIFIED);
> >> +	} else if (temp < sensor->thres_temp) {
> >> +		dev_crit(&data->pdev->dev, "THERMAL ALARM stopped: %d < %d\n",
> >> +			 temp, sensor->thres_temp);
> >> +	}
> > 
> > For temperature increasing and decreasing both cases, can always call
> > thermal_zone_device_update()?
> 
> That is something I asked myself but I finally decided to not change the
> current behavior and let that be added in a separate patch.

This is fine.

Thanks,
Leo Yan

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#1726008 — Re: [PATCH 09/13] thermal/drivers/hisi: Remove costly sensor inspection

On 04/09/2017 02:50, Leo Yan wrote:

[ ... ]

>> That is something I asked myself but I finally decided to not change the
>> current behavior and let that be added in a separate patch.
> 
> This is fine.

Hi Leo,

can you tag this patch if you agree with it?

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#1726119 — Re: [PATCH 09/13] thermal/drivers/hisi: Remove costly sensor inspection

On Mon, Sep 04, 2017 at 01:29:19PM +0200, Daniel Lezcano wrote:
> On 04/09/2017 02:50, Leo Yan wrote:
> 
> [ ... ]
> 
> >> That is something I asked myself but I finally decided to not change the
> >> current behavior and let that be added in a separate patch.
> > 
> > This is fine.
> 
> Hi Leo,
> 
> can you tag this patch if you agree with it?

Yeah; I have tested this patch at my side:

Reviewed-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Leo Yan <leo.yan@linaro.org>

> 
> -- 
>  <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
> 
> Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
> <http://twitter.com/#!/linaroorg> Twitter |
> <http://www.linaro.org/linaro-blog/> Blog
> 

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#1723134 — [PATCH 05/13] thermal/drivers/hisi: Fix multiple alarm interrupts firing

The DT specifies a threshold of 65000, we setup the register with a value in
the temperature resolution for the controller, 64656.

When we reach 64656, the interrupt fires, the interrupt is disabled. Then the
irq thread runs and calls thermal_zone_device_update() which will call in turn
hisi_thermal_get_temp().

The function will look if the temperature decreased, assuming it was more than
65000, but that is not the case because the current temperature is 64656
(because of the rounding when setting the threshold). This condition being
true, we re-enable the interrupt which fires immediately after exiting the irq
thread. That happens again and again until the temperature goes to more than
65000.

Potentially, there is here an interrupt storm if the temperature stabilizes at
this temperature. A very unlikely case but possible.

In any case, it does not make sense to handle dozens of alarm interrupt for
nothing.

Fix this by rounding the threshold value to the controller resolution so the
check against the threshold is consistent with the one set in the controller.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/thermal/hisi_thermal.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
index b58ad40..524310d 100644
--- a/drivers/thermal/hisi_thermal.c
+++ b/drivers/thermal/hisi_thermal.c
@@ -90,6 +90,12 @@ static inline long hisi_thermal_temp_to_step(long temp)
 	return (temp - HISI_TEMP_BASE) / HISI_TEMP_STEP;
 }
 
+static inline long hisi_thermal_round_temp(int temp)
+{
+	return hisi_thermal_step_to_temp(
+		hisi_thermal_temp_to_step(temp));
+}
+
 static long hisi_thermal_get_sensor_temp(struct hisi_thermal_data *data,
 					 struct hisi_thermal_sensor *sensor)
 {
@@ -221,7 +227,7 @@ static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
 	sensor = &data->sensors;
 
 	dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",
-		 sensor->thres_temp / 1000);
+		 sensor->thres_temp);
 	mutex_unlock(&data->thermal_lock);
 
 	thermal_zone_device_update(data->sensors.tzd,
@@ -255,7 +261,7 @@ static int hisi_thermal_register_sensor(struct platform_device *pdev,
 
 	for (i = 0; i < of_thermal_get_ntrips(sensor->tzd); i++) {
 		if (trip[i].type == THERMAL_TRIP_PASSIVE) {
-			sensor->thres_temp = trip[i].temperature;
+			sensor->thres_temp = hisi_thermal_round_temp(trip[i].temperature);
 			break;
 		}
 	}
-- 
2.7.4

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