diff mbox series

[v5,1/4] PM / devfreq: Register devfreq as a cooling device on demand

Message ID 20210308091646.28096-1-daniel.lezcano@linaro.org
State Superseded
Headers show
Series [v5,1/4] PM / devfreq: Register devfreq as a cooling device on demand | expand

Commit Message

Daniel Lezcano March 8, 2021, 9:16 a.m. UTC
Currently the default behavior is to manually having the devfreq
backend to register themselves as a devfreq cooling device.

Instead of adding the code in the drivers for the thermal cooling
device registering, let's provide a flag in the devfreq's profile to
tell the common devfreq code to register the newly created devfreq as
a cooling device.

Suggested-by: Chanwoo Choi <cwchoi00@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

---
 V5:
   - Changed subject prefix by:  PM / devfreq
 V4:
   - Replaced thermal_cooling_device_unregister() by
     devfreq_cooling_unregister()
 V3:
   - Rebased on linux-pm branch without units.h
   - Set the cdev to NULL in case of error
   - Added description for the cdev field in the devfreq structure
 V2:
   - Added is_cooling_device boolean in profile structure
   - Register cooling device when the is_cooling_device boolean is set
   - Remove devfreq cooling device registration in the backend drivers
 V1:
   - Register devfreq as a cooling device unconditionnally
---
 drivers/devfreq/devfreq.c | 13 +++++++++++++
 include/linux/devfreq.h   |  8 ++++++++
 2 files changed, 21 insertions(+)

-- 
2.17.1

Comments

Steven Price March 8, 2021, 9:51 a.m. UTC | #1
On 08/03/2021 09:16, Daniel Lezcano wrote:
> Currently the default behavior is to manually having the devfreq

> backend to register themselves as a devfreq cooling device.

> 

> Instead of adding the code in the drivers for the thermal cooling

> device registering, let's provide a flag in the devfreq's profile to

> tell the common devfreq code to register the newly created devfreq as

> a cooling device.

> 

> Suggested-by: Chanwoo Choi <cwchoi00@gmail.com>

> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

> ---

>   V5:

>     - Changed subject prefix by:  PM / devfreq

>   V4:

>     - Replaced thermal_cooling_device_unregister() by

>       devfreq_cooling_unregister()

>   V3:

>     - Rebased on linux-pm branch without units.h

>     - Set the cdev to NULL in case of error

>     - Added description for the cdev field in the devfreq structure

>   V2:

>     - Added is_cooling_device boolean in profile structure

>     - Register cooling device when the is_cooling_device boolean is set

>     - Remove devfreq cooling device registration in the backend drivers

>   V1:

>     - Register devfreq as a cooling device unconditionnally

> ---

>   drivers/devfreq/devfreq.c | 13 +++++++++++++

>   include/linux/devfreq.h   |  8 ++++++++

>   2 files changed, 21 insertions(+)

> 

> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c

> index bf3047896e41..8a535d4d6083 100644

> --- a/drivers/devfreq/devfreq.c

> +++ b/drivers/devfreq/devfreq.c

> @@ -11,6 +11,7 @@

>   #include <linux/kmod.h>

>   #include <linux/sched.h>

>   #include <linux/debugfs.h>

> +#include <linux/devfreq_cooling.h>

>   #include <linux/errno.h>

>   #include <linux/err.h>

>   #include <linux/init.h>

> @@ -26,6 +27,7 @@

>   #include <linux/hrtimer.h>

>   #include <linux/of.h>

>   #include <linux/pm_qos.h>

> +#include <linux/thermal.h>

>   #include "governor.h"

>   

>   #define CREATE_TRACE_POINTS

> @@ -935,6 +937,15 @@ struct devfreq *devfreq_add_device(struct device *dev,

>   

>   	mutex_unlock(&devfreq_list_lock);

>   

> +	if (devfreq->profile->is_cooling_device) {

> +		devfreq->cdev = devfreq_cooling_em_register(devfreq, NULL);

> +		if (IS_ERR(devfreq->cdev)) {

> +			dev_info(dev, "Failed to register devfreq "

> +				 "cooling device\n");


Please don't split strings across multiple lines (it makes grepping for 
them harder). With that fixed:

Reviewed-by: Steven Price <steven.price@arm.com>


> +			devfreq->cdev = NULL;

> +		}

> +	}

> +

>   	return devfreq;

>   

>   err_init:

> @@ -960,6 +971,8 @@ int devfreq_remove_device(struct devfreq *devfreq)

>   	if (!devfreq)

>   		return -EINVAL;

>   

> +	devfreq_cooling_unregister(devfreq->cdev);

> +

>   	if (devfreq->governor) {

>   		devfreq->governor->event_handler(devfreq,

>   						 DEVFREQ_GOV_STOP, NULL);

> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h

> index 26ea0850be9b..aba7ace11b72 100644

> --- a/include/linux/devfreq.h

> +++ b/include/linux/devfreq.h

> @@ -98,11 +98,15 @@ struct devfreq_dev_status {

>    * @freq_table:		Optional list of frequencies to support statistics

>    *			and freq_table must be generated in ascending order.

>    * @max_state:		The size of freq_table.

> + *

> + * @is_cooling_device: A self-explanatory boolean giving the device a

> + *                     cooling effect property.

>    */

>   struct devfreq_dev_profile {

>   	unsigned long initial_freq;

>   	unsigned int polling_ms;

>   	enum devfreq_timer timer;

> +	bool is_cooling_device;

>   

>   	int (*target)(struct device *dev, unsigned long *freq, u32 flags);

>   	int (*get_dev_status)(struct device *dev,

> @@ -156,6 +160,7 @@ struct devfreq_stats {

>    * @suspend_count:	 suspend requests counter for a device.

>    * @stats:	Statistics of devfreq device behavior

>    * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier

> + * @cdev:	Cooling device pointer if the devfreq has cooling property

>    * @nb_min:		Notifier block for DEV_PM_QOS_MIN_FREQUENCY

>    * @nb_max:		Notifier block for DEV_PM_QOS_MAX_FREQUENCY

>    *

> @@ -198,6 +203,9 @@ struct devfreq {

>   

>   	struct srcu_notifier_head transition_notifier_list;

>   

> +	/* Pointer to the cooling device if used for thermal mitigation */

> +	struct thermal_cooling_device *cdev;

> +

>   	struct notifier_block nb_min;

>   	struct notifier_block nb_max;

>   };

>
Steven Price March 8, 2021, 9:51 a.m. UTC | #2
On 08/03/2021 09:16, Daniel Lezcano wrote:
> The devfreq core code is able to register the devfreq device as a
> cooling device if the 'is_cooling_device' flag is set in the profile.
> 
> Use this flag and remove the cooling device registering code.
> 
> Tested on rock960.
> 
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Reviewed-by: Steven Price <steven.price@arm.com>

> ---
>   drivers/gpu/drm/panfrost/panfrost_devfreq.c | 14 +-------------
>   drivers/gpu/drm/panfrost/panfrost_devfreq.h |  3 ---
>   2 files changed, 1 insertion(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> index 56b3f5935703..4d96edf1bc54 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> @@ -3,7 +3,6 @@
>   
>   #include <linux/clk.h>
>   #include <linux/devfreq.h>
> -#include <linux/devfreq_cooling.h>
>   #include <linux/platform_device.h>
>   #include <linux/pm_opp.h>
>   
> @@ -80,6 +79,7 @@ static struct devfreq_dev_profile panfrost_devfreq_profile = {
>   	.polling_ms = 50, /* ~3 frames */
>   	.target = panfrost_devfreq_target,
>   	.get_dev_status = panfrost_devfreq_get_dev_status,
> +	.is_cooling_device = true,
>   };
>   
>   int panfrost_devfreq_init(struct panfrost_device *pfdev)
> @@ -90,7 +90,6 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
>   	struct device *dev = &pfdev->pdev->dev;
>   	struct devfreq *devfreq;
>   	struct opp_table *opp_table;
> -	struct thermal_cooling_device *cooling;
>   	struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
>   
>   	opp_table = dev_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
> @@ -139,12 +138,6 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
>   	}
>   	pfdevfreq->devfreq = devfreq;
>   
> -	cooling = devfreq_cooling_em_register(devfreq, NULL);
> -	if (IS_ERR(cooling))
> -		DRM_DEV_INFO(dev, "Failed to register cooling device\n");
> -	else
> -		pfdevfreq->cooling = cooling;
> -
>   	return 0;
>   
>   err_fini:
> @@ -156,11 +149,6 @@ void panfrost_devfreq_fini(struct panfrost_device *pfdev)
>   {
>   	struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
>   
> -	if (pfdevfreq->cooling) {
> -		devfreq_cooling_unregister(pfdevfreq->cooling);
> -		pfdevfreq->cooling = NULL;
> -	}
> -
>   	if (pfdevfreq->opp_of_table_added) {
>   		dev_pm_opp_of_remove_table(&pfdev->pdev->dev);
>   		pfdevfreq->opp_of_table_added = false;
> diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.h b/drivers/gpu/drm/panfrost/panfrost_devfreq.h
> index db6ea48e21f9..470f5c974703 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.h
> @@ -9,14 +9,11 @@
>   
>   struct devfreq;
>   struct opp_table;
> -struct thermal_cooling_device;
> -
>   struct panfrost_device;
>   
>   struct panfrost_devfreq {
>   	struct devfreq *devfreq;
>   	struct opp_table *regulators_opp_table;
> -	struct thermal_cooling_device *cooling;
>   	bool opp_of_table_added;
>   
>   	ktime_t busy_time;
>
Lukasz Luba March 8, 2021, 9:53 a.m. UTC | #3
Hi Daniel,

In general the approach is good. If there is a special GPU driver, which
would like to provide 'struct devfreq_cooling_power *' it would leave
'is_cooling_device=false' and register manually:
devfreq_cooling_em_register(df, dfc_power);

Please find only a few minor comments below.


On 3/8/21 9:16 AM, Daniel Lezcano wrote:
> Currently the default behavior is to manually having the devfreq

> backend to register themselves as a devfreq cooling device.

> 

> Instead of adding the code in the drivers for the thermal cooling

> device registering, let's provide a flag in the devfreq's profile to

> tell the common devfreq code to register the newly created devfreq as

> a cooling device.

> 

> Suggested-by: Chanwoo Choi <cwchoi00@gmail.com>

> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

> ---

>   V5:

>     - Changed subject prefix by:  PM / devfreq

>   V4:

>     - Replaced thermal_cooling_device_unregister() by

>       devfreq_cooling_unregister()

>   V3:

>     - Rebased on linux-pm branch without units.h

>     - Set the cdev to NULL in case of error

>     - Added description for the cdev field in the devfreq structure

>   V2:

>     - Added is_cooling_device boolean in profile structure

>     - Register cooling device when the is_cooling_device boolean is set

>     - Remove devfreq cooling device registration in the backend drivers

>   V1:

>     - Register devfreq as a cooling device unconditionnally

> ---

>   drivers/devfreq/devfreq.c | 13 +++++++++++++

>   include/linux/devfreq.h   |  8 ++++++++

>   2 files changed, 21 insertions(+)

> 

> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c

> index bf3047896e41..8a535d4d6083 100644

> --- a/drivers/devfreq/devfreq.c

> +++ b/drivers/devfreq/devfreq.c

> @@ -11,6 +11,7 @@

>   #include <linux/kmod.h>

>   #include <linux/sched.h>

>   #include <linux/debugfs.h>

> +#include <linux/devfreq_cooling.h>

>   #include <linux/errno.h>

>   #include <linux/err.h>

>   #include <linux/init.h>

> @@ -26,6 +27,7 @@

>   #include <linux/hrtimer.h>

>   #include <linux/of.h>

>   #include <linux/pm_qos.h>

> +#include <linux/thermal.h>


Since the unregister is now called from devfreq_cooling.h, this header
here is not needed. It might rather be moved into the devfreq.h
where there is this new field: 'cdev' if we are going to use something
from it.

>   #include "governor.h"

>   

>   #define CREATE_TRACE_POINTS

> @@ -935,6 +937,15 @@ struct devfreq *devfreq_add_device(struct device *dev,

>   

>   	mutex_unlock(&devfreq_list_lock);

>   

> +	if (devfreq->profile->is_cooling_device) {

> +		devfreq->cdev = devfreq_cooling_em_register(devfreq, NULL);

> +		if (IS_ERR(devfreq->cdev)) {

> +			dev_info(dev, "Failed to register devfreq "

> +				 "cooling device\n");


I would skip this print. Not every kernel config has DEVFREQ_THERMAL set
and the value ERR_PTR(-EINVAL) from header would be returned in such
case.
Inside the devfreq_cooling_em_register() (and others) there are prints
showing that something wrong happen and would be triggered if compiled.

> +			devfreq->cdev = NULL;

> +		}

> +	}

> +

>   	return devfreq;

>   

>   err_init:

> @@ -960,6 +971,8 @@ int devfreq_remove_device(struct devfreq *devfreq)

>   	if (!devfreq)

>   		return -EINVAL;

>   

> +	devfreq_cooling_unregister(devfreq->cdev);

> +

>   	if (devfreq->governor) {

>   		devfreq->governor->event_handler(devfreq,

>   						 DEVFREQ_GOV_STOP, NULL);

> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h

> index 26ea0850be9b..aba7ace11b72 100644

> --- a/include/linux/devfreq.h

> +++ b/include/linux/devfreq.h

> @@ -98,11 +98,15 @@ struct devfreq_dev_status {

>    * @freq_table:		Optional list of frequencies to support statistics

>    *			and freq_table must be generated in ascending order.

>    * @max_state:		The size of freq_table.

> + *

> + * @is_cooling_device: A self-explanatory boolean giving the device a

> + *                     cooling effect property.

>    */

>   struct devfreq_dev_profile {

>   	unsigned long initial_freq;

>   	unsigned int polling_ms;

>   	enum devfreq_timer timer;

> +	bool is_cooling_device;

>   

>   	int (*target)(struct device *dev, unsigned long *freq, u32 flags);

>   	int (*get_dev_status)(struct device *dev,

> @@ -156,6 +160,7 @@ struct devfreq_stats {

>    * @suspend_count:	 suspend requests counter for a device.

>    * @stats:	Statistics of devfreq device behavior

>    * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier

> + * @cdev:	Cooling device pointer if the devfreq has cooling property

>    * @nb_min:		Notifier block for DEV_PM_QOS_MIN_FREQUENCY

>    * @nb_max:		Notifier block for DEV_PM_QOS_MAX_FREQUENCY

>    *

> @@ -198,6 +203,9 @@ struct devfreq {

>   

>   	struct srcu_notifier_head transition_notifier_list;

>   

> +	/* Pointer to the cooling device if used for thermal mitigation */

> +	struct thermal_cooling_device *cdev;


The linux/thermal.h for 'cdev' would be needed in this header.

> +

>   	struct notifier_block nb_min;

>   	struct notifier_block nb_max;

>   };

> 


With this small changes:

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>


Regards,
Lukasz
Daniel Lezcano March 8, 2021, noon UTC | #4
On 08/03/2021 10:53, Lukasz Luba wrote:
> Hi Daniel,

> 

> In general the approach is good. If there is a special GPU driver, which

> would like to provide 'struct devfreq_cooling_power *' it would leave

> 'is_cooling_device=false' and register manually:

> devfreq_cooling_em_register(df, dfc_power);

> 

> Please find only a few minor comments below.

> 

> 

> On 3/8/21 9:16 AM, Daniel Lezcano wrote:

>> Currently the default behavior is to manually having the devfreq

>> backend to register themselves as a devfreq cooling device.

>>

>> Instead of adding the code in the drivers for the thermal cooling

>> device registering, let's provide a flag in the devfreq's profile to

>> tell the common devfreq code to register the newly created devfreq as

>> a cooling device.

>>

>> Suggested-by: Chanwoo Choi <cwchoi00@gmail.com>

>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

>> ---


[ ... ]

>> +    struct thermal_cooling_device *cdev;

> 

> The linux/thermal.h for 'cdev' would be needed in this header.


May be just a forward declaration ?

struct thermal_cooling_device;

>> +

>>       struct notifier_block nb_min;

>>       struct notifier_block nb_max;

>>   };

>>

> 

> With this small changes:

> 

> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>

> 

> Regards,

> Lukasz



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Lukasz Luba March 8, 2021, 12:04 p.m. UTC | #5
On 3/8/21 12:00 PM, Daniel Lezcano wrote:
> On 08/03/2021 10:53, Lukasz Luba wrote:

>> Hi Daniel,

>>

>> In general the approach is good. If there is a special GPU driver, which

>> would like to provide 'struct devfreq_cooling_power *' it would leave

>> 'is_cooling_device=false' and register manually:

>> devfreq_cooling_em_register(df, dfc_power);

>>

>> Please find only a few minor comments below.

>>

>>

>> On 3/8/21 9:16 AM, Daniel Lezcano wrote:

>>> Currently the default behavior is to manually having the devfreq

>>> backend to register themselves as a devfreq cooling device.

>>>

>>> Instead of adding the code in the drivers for the thermal cooling

>>> device registering, let's provide a flag in the devfreq's profile to

>>> tell the common devfreq code to register the newly created devfreq as

>>> a cooling device.

>>>

>>> Suggested-by: Chanwoo Choi <cwchoi00@gmail.com>

>>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

>>> ---

> 

> [ ... ]

> 

>>> +    struct thermal_cooling_device *cdev;

>>

>> The linux/thermal.h for 'cdev' would be needed in this header.

> 

> May be just a forward declaration ?

> 

> struct thermal_cooling_device;


Make sense

Regards,
Lukasz
diff mbox series

Patch

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index bf3047896e41..8a535d4d6083 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -11,6 +11,7 @@ 
 #include <linux/kmod.h>
 #include <linux/sched.h>
 #include <linux/debugfs.h>
+#include <linux/devfreq_cooling.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/init.h>
@@ -26,6 +27,7 @@ 
 #include <linux/hrtimer.h>
 #include <linux/of.h>
 #include <linux/pm_qos.h>
+#include <linux/thermal.h>
 #include "governor.h"
 
 #define CREATE_TRACE_POINTS
@@ -935,6 +937,15 @@  struct devfreq *devfreq_add_device(struct device *dev,
 
 	mutex_unlock(&devfreq_list_lock);
 
+	if (devfreq->profile->is_cooling_device) {
+		devfreq->cdev = devfreq_cooling_em_register(devfreq, NULL);
+		if (IS_ERR(devfreq->cdev)) {
+			dev_info(dev, "Failed to register devfreq "
+				 "cooling device\n");
+			devfreq->cdev = NULL;
+		}
+	}
+
 	return devfreq;
 
 err_init:
@@ -960,6 +971,8 @@  int devfreq_remove_device(struct devfreq *devfreq)
 	if (!devfreq)
 		return -EINVAL;
 
+	devfreq_cooling_unregister(devfreq->cdev);
+
 	if (devfreq->governor) {
 		devfreq->governor->event_handler(devfreq,
 						 DEVFREQ_GOV_STOP, NULL);
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 26ea0850be9b..aba7ace11b72 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -98,11 +98,15 @@  struct devfreq_dev_status {
  * @freq_table:		Optional list of frequencies to support statistics
  *			and freq_table must be generated in ascending order.
  * @max_state:		The size of freq_table.
+ *
+ * @is_cooling_device: A self-explanatory boolean giving the device a
+ *                     cooling effect property.
  */
 struct devfreq_dev_profile {
 	unsigned long initial_freq;
 	unsigned int polling_ms;
 	enum devfreq_timer timer;
+	bool is_cooling_device;
 
 	int (*target)(struct device *dev, unsigned long *freq, u32 flags);
 	int (*get_dev_status)(struct device *dev,
@@ -156,6 +160,7 @@  struct devfreq_stats {
  * @suspend_count:	 suspend requests counter for a device.
  * @stats:	Statistics of devfreq device behavior
  * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
+ * @cdev:	Cooling device pointer if the devfreq has cooling property
  * @nb_min:		Notifier block for DEV_PM_QOS_MIN_FREQUENCY
  * @nb_max:		Notifier block for DEV_PM_QOS_MAX_FREQUENCY
  *
@@ -198,6 +203,9 @@  struct devfreq {
 
 	struct srcu_notifier_head transition_notifier_list;
 
+	/* Pointer to the cooling device if used for thermal mitigation */
+	struct thermal_cooling_device *cdev;
+
 	struct notifier_block nb_min;
 	struct notifier_block nb_max;
 };