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* [PATCHv7 02/10] devfreq: event: Add the list of supported devfreq-event type
  2015-01-07 23:51 [PATCHv7 00/10] devfreq: Add devfreq-event class to provide raw data for devfreq device Chanwoo Choi
@ 2015-01-07 23:51 ` Chanwoo Choi
  0 siblings, 0 replies; 2+ messages in thread
From: Chanwoo Choi @ 2015-01-07 23:51 UTC (permalink / raw)
  To: linux-arm-kernel

This patch adds the list of supported devfreq-event type as following.
Each devfreq-event device driver would support the various devfreq-event type
for devfreq governor at the same time.
- DEVFREQ_EVENT_TYPE_RAW_DATA
- DEVFREQ_EVENT_TYPE_UTILIZATION
- DEVFREQ_EVENT_TYPE_BANDWIDTH
- DEVFREQ_EVENT_TYPE_LATENCY

Cc: MyungJoo Ham <myungjoo.ham@samsung•com>
Cc: Kyungmin Park <kyungmin.park@samsung•com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung•com>
---
 drivers/devfreq/devfreq-event.c | 58 ++++++++++++++++++++++++++++++++++++-----
 include/linux/devfreq-event.h   | 25 +++++++++++++++---
 2 files changed, 73 insertions(+), 10 deletions(-)

diff --git a/drivers/devfreq/devfreq-event.c b/drivers/devfreq/devfreq-event.c
index 81448ba..64c1764 100644
--- a/drivers/devfreq/devfreq-event.c
+++ b/drivers/devfreq/devfreq-event.c
@@ -20,6 +20,9 @@
 #include <linux/list.h>
 #include <linux/of.h>
 
+#define EVENT_TYPE_RAW_DATA_MAX		ULONG_MAX
+#define EVENT_TYPE_UTILIZATION_MAX	100
+
 static struct class *devfreq_event_class;
 
 /* The list of all devfreq event list */
@@ -132,7 +135,8 @@ EXPORT_SYMBOL_GPL(devfreq_event_is_enabled);
  * Note that this function set the event to the devfreq-event device to start
  * for getting the event data which could be various event type.
  */
-int devfreq_event_set_event(struct devfreq_event_dev *edev)
+int devfreq_event_set_event(struct devfreq_event_dev *edev,
+				enum devfreq_event_type type)
 {
 	int ret;
 
@@ -146,7 +150,15 @@ int devfreq_event_set_event(struct devfreq_event_dev *edev)
 		return -EPERM;
 
 	mutex_lock(&edev->lock);
-	ret = edev->desc->ops->set_event(edev);
+
+	if ((edev->desc->type & type) == 0) {
+		dev_err(&edev->dev, "unsupported devfreq-event type\n");
+		mutex_unlock(&edev->lock);
+		return -EINVAL;
+	}
+
+	ret = edev->desc->ops->set_event(edev, type);
+
 	mutex_unlock(&edev->lock);
 
 	return ret;
@@ -162,6 +174,7 @@ EXPORT_SYMBOL_GPL(devfreq_event_set_event);
  * after stoping the progress of whole sequence of devfreq-event dev.
  */
 int devfreq_event_get_event(struct devfreq_event_dev *edev,
+			    enum devfreq_event_type type,
 			    struct devfreq_event_data *edata)
 {
 	int ret;
@@ -175,18 +188,49 @@ int devfreq_event_get_event(struct devfreq_event_dev *edev,
 	if (!devfreq_event_is_enabled(edev))
 		return -EINVAL;
 
+	mutex_lock(&edev->lock);
+
+	if ((edev->desc->type & type) == 0) {
+		dev_err(&edev->dev, "unsupported devfreq-event type\n");
+		return -EINVAL;
+	}
+
 	edata->event = edata->total_event = 0;
+	ret = edev->desc->ops->get_event(edev, type, edata);
+	if (ret < 0
+		|| edata->total_event <= 0
+		|| edata->event > edata->total_event) {
+		edata->event = edata->total_event = 0;
+		mutex_unlock(&edev->lock);
+		return -EINVAL;
+	}
 
-	mutex_lock(&edev->lock);
-	ret = edev->desc->ops->get_event(edev, edata);
-	mutex_unlock(&edev->lock);
+	switch (type) {
+	case DEVFREQ_EVENT_TYPE_RAW_DATA:
+	case DEVFREQ_EVENT_TYPE_BANDWIDTH:
+	case DEVFREQ_EVENT_TYPE_LATENCY:
+		if ((edata->event > EVENT_TYPE_RAW_DATA_MAX) ||
+			(edata->total_event > EVENT_TYPE_RAW_DATA_MAX)) {
+			edata->event = edata->total_event = 0;
+			ret = -EINVAL;
+		}
+		break;
+	case DEVFREQ_EVENT_TYPE_UTILIZATION:
+		edata->total_event = EVENT_TYPE_UTILIZATION_MAX;
 
-	if ((edata->total_event <= 0)
-		|| (edata->event > edata->total_event)) {
+		if (edata->event > EVENT_TYPE_UTILIZATION_MAX) {
+			edata->event = edata->total_event = 0;
+			ret = -EINVAL;
+		}
+		break;
+	default:
 		edata->event = edata->total_event = 0;
 		ret = -EINVAL;
+		break;
 	}
 
+	mutex_unlock(&edev->lock);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(devfreq_event_get_event);
diff --git a/include/linux/devfreq-event.h b/include/linux/devfreq-event.h
index b7363f5..13a5703 100644
--- a/include/linux/devfreq-event.h
+++ b/include/linux/devfreq-event.h
@@ -36,6 +36,14 @@ struct devfreq_event_dev {
 	const struct devfreq_event_desc *desc;
 };
 
+/* The supported type by devfreq-event device */
+enum devfreq_event_type {
+	DEVFREQ_EVENT_TYPE_RAW_DATA	= BIT(0),
+	DEVFREQ_EVENT_TYPE_UTILIZATION	= BIT(1),
+	DEVFREQ_EVENT_TYPE_BANDWIDTH	= BIT(2),
+	DEVFREQ_EVENT_TYPE_LATENCY	= BIT(3),
+};
+
 /**
  * struct devfreq_event_data - the devfreq-event data
  *
@@ -69,8 +77,10 @@ struct devfreq_event_ops {
 	int (*reset)(struct devfreq_event_dev *edev);
 
 	/* Mandatory functions */
-	int (*set_event)(struct devfreq_event_dev *edev);
+	int (*set_event)(struct devfreq_event_dev *edev,
+			 enum devfreq_event_type type);
 	int (*get_event)(struct devfreq_event_dev *edev,
+			 enum devfreq_event_type type,
 			 struct devfreq_event_data *edata);
 };
 
@@ -79,6 +89,10 @@ struct devfreq_event_ops {
  *
  * @name	: the name of devfreq-event device.
  * @driver_data	: the private data for devfreq-event driver.
+ * @event_type	: the supported devfreq-event type among as following
+ *		  - DEVFREQ_EVENT_TYPE_UTILIZATION
+ *		  - DEVFREQ_EVENT_TYPE_BANDWIDTH
+ *		  - DEVFREQ_EVENT_TYPE_LATENCY
  * @ops		: the operation to control devfreq-event device.
  *
  * Each devfreq-event device is described with a this structure.
@@ -87,6 +101,7 @@ struct devfreq_event_ops {
 struct devfreq_event_desc {
 	const char *name;
 	void *driver_data;
+	enum devfreq_event_type type;
 
 	struct devfreq_event_ops *ops;
 };
@@ -95,8 +110,10 @@ struct devfreq_event_desc {
 extern int devfreq_event_enable_edev(struct devfreq_event_dev *edev);
 extern int devfreq_event_disable_edev(struct devfreq_event_dev *edev);
 extern bool devfreq_event_is_enabled(struct devfreq_event_dev *edev);
-extern int devfreq_event_set_event(struct devfreq_event_dev *edev);
+extern int devfreq_event_set_event(struct devfreq_event_dev *edev,
+				enum devfreq_event_type type);
 extern int devfreq_event_get_event(struct devfreq_event_dev *edev,
+				enum devfreq_event_type type,
 				struct devfreq_event_data *edata);
 extern int devfreq_event_reset_event(struct devfreq_event_dev *edev);
 extern void *devfreq_event_get_drvdata(struct devfreq_event_dev *edev);
@@ -123,12 +140,14 @@ static inline bool devfreq_event_is_enabled(struct devfreq_event_dev *edev)
 	return false;
 }
 
-static inline int devfreq_event_set_event(struct devfreq_event_dev *edev)
+static inline int devfreq_event_set_event(struct devfreq_event_dev *edev,
+					enum devfreq_event_type type)
 {
 	return -EINVAL;
 }
 
 static inline int devfreq_event_get_event(struct devfreq_event_dev *edev,
+					enum devfreq_event_type type,
 					struct devfreq_event_data *edata)
 {
 	return -EINVAL;
-- 
1.8.5.5

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* [PATCHv7 02/10] devfreq: event: Add the list of supported devfreq-event type
       [not found] <768125446.886831421046952335.JavaMail.weblogic@epmlwas09a>
@ 2015-01-12 11:17 ` Chanwoo Choi
  0 siblings, 0 replies; 2+ messages in thread
From: Chanwoo Choi @ 2015-01-12 11:17 UTC (permalink / raw)
  To: linux-arm-kernel

Dear Myungjoo,

On 01/12/2015 04:15 PM, MyungJoo Ham wrote:
>>   
>>  This patch adds the list of supported devfreq-event type as following.
>> Each devfreq-event device driver would support the various devfreq-event type
>> for devfreq governor at the same time.
>> - DEVFREQ_EVENT_TYPE_RAW_DATA
>> - DEVFREQ_EVENT_TYPE_UTILIZATION
>> - DEVFREQ_EVENT_TYPE_BANDWIDTH
>> - DEVFREQ_EVENT_TYPE_LATENCY
> 
> Did you try to say:
> 
> A devfreq-event device may support multiple devfreq-event types
> simultaneously.

I think that one devfreq-event device can support multiple devfreq-event types.
but, devfreq-event device might provide only value at one point.

But,
This patch is ambiguous and includes a bug according to your comment
(below switch statement). I'll drop this patch on next patch-set.

This patch will be posted on further patch-set after resolving some issue.

Best Regards,
Chanwoo Choi

> 
> If so, your switch expressions are going to screw up.
> 
> 
>>
>> Cc: MyungJoo Ham <myungjoo.ham@samsung•com>
>> Cc: Kyungmin Park <kyungmin.park@samsung•com>
>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung•com>
>> ---
>>  drivers/devfreq/devfreq-event.c | 58 ++++++++++++++++++++++++++++++++++++-----
>>  include/linux/devfreq-event.h   | 25 +++++++++++++++---
>>  2 files changed, 73 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/devfreq/devfreq-event.c b/drivers/devfreq/devfreq-event.c
>> index 81448ba..64c1764 100644
>> --- a/drivers/devfreq/devfreq-event.c
>> +++ b/drivers/devfreq/devfreq-event.c
>>  
> []
>> -	mutex_lock(&edev->lock);
>> -	ret = edev->desc->ops->get_event(edev, edata);
>> -	mutex_unlock(&edev->lock);
>> +	switch (type) {
> 
> Bitwise value with switch? (what if type = RAW_DATA | BANDWIDTH, meaning
> this is raw data of the bandwitdh.)
> 
>> +	case DEVFREQ_EVENT_TYPE_RAW_DATA:
>> +	case DEVFREQ_EVENT_TYPE_BANDWIDTH:
>> +	case DEVFREQ_EVENT_TYPE_LATENCY:
>> +		if ((edata->event > EVENT_TYPE_RAW_DATA_MAX) ||
>> +			(edata->total_event > EVENT_TYPE_RAW_DATA_MAX)) {
> 
> Is it possible for unsigned long edata->event/total_event to be
>   > EVENT_TYPE_RAW_DATA_MAX = ULONG_MAX?
> 
> What was your intention?
> 
> If you were trying to detect overflow, you need to rethink about it.
> If not, (overflow is harmless or not going to happen) you don't need to
> check it.
> 
> 
>> +			edata->event = edata->total_event = 0;
>> +			ret = -EINVAL;
>> +		}
>> +		break;
>> +	case DEVFREQ_EVENT_TYPE_UTILIZATION:
>> +		edata->total_event = EVENT_TYPE_UTILIZATION_MAX;
>>  
>> -	if ((edata->total_event <= 0)
>> -		|| (edata->event > edata->total_event)) {
>> +		if (edata->event > EVENT_TYPE_UTILIZATION_MAX) {
>> +			edata->event = edata->total_event = 0;
>> +			ret = -EINVAL;
>> +		}
>> +		break;
>> +	default:
>>  		edata->event = edata->total_event = 0;
>>  		ret = -EINVAL;
>> +		break;
>>  	}
>>  
>> +	mutex_unlock(&edev->lock);
>> +
>>  	return ret;
>>  }
>>  EXPORT_SYMBOL_GPL(devfreq_event_get_event);
>> diff --git a/include/linux/devfreq-event.h b/include/linux/devfreq-event.h
>> index b7363f5..13a5703 100644
>> --- a/include/linux/devfreq-event.h
>> +++ b/include/linux/devfreq-event.h
>> @@ -36,6 +36,14 @@ struct devfreq_event_dev {
>>  	const struct devfreq_event_desc *desc;
>>  };
>>  
>> +/* The supported type by devfreq-event device */
>> +enum devfreq_event_type {
>> +	DEVFREQ_EVENT_TYPE_RAW_DATA	= BIT(0),
>> +	DEVFREQ_EVENT_TYPE_UTILIZATION	= BIT(1),
>> +	DEVFREQ_EVENT_TYPE_BANDWIDTH	= BIT(2),
>> +	DEVFREQ_EVENT_TYPE_LATENCY	= BIT(3),
>> +};
>> +
> 
> (Being curious) Is it possible to have multiple types
> simultaneously?
> 
> 
> []
> N?????r??y???b?X???v?^?)?{.n?+????{?????x,???\x17???}????z?&j:+v???\a????zZ+??+zf???h???~????i???z?
?w????????&?)?^[fl===
> 

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2015-01-12 11:17 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
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2015-01-12 11:17 ` [PATCHv7 02/10] devfreq: event: Add the list of supported devfreq-event type Chanwoo Choi
2015-01-07 23:51 [PATCHv7 00/10] devfreq: Add devfreq-event class to provide raw data for devfreq device Chanwoo Choi
2015-01-07 23:51 ` [PATCHv7 02/10] devfreq: event: Add the list of supported devfreq-event type Chanwoo Choi

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