diff mbox series

[RESEND,7/8] thermal: cooling: Check Energy Model type in cpufreq_cooling and devfreq_cooling

Message ID 20220321095729.20655-8-lukasz.luba@arm.com
State Accepted
Commit 9926bbec3ae6c10d4e6fc297afde6a7ef7ad640b
Headers show
Series Introduce support for artificial Energy Model | expand

Commit Message

Lukasz Luba March 21, 2022, 9:57 a.m. UTC
The Energy Model can now be artificial, which means the power values
are mathematically generated to leverage EAS while not expected to be on
an uniform scale with other devices providing power information. If this
EM type is in use, the thermal governor IPA should not be allowed to
operate, since the relation between cooling devices is not properly
defined. Thus, it might be possible that big GPU has lower power values
than a Little CPU. To mitigate a misbehaviour of the thermal control
algorithm, simply do not register the cooling device as IPA's power
actor.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
---
 drivers/thermal/cpufreq_cooling.c | 2 +-
 drivers/thermal/devfreq_cooling.c | 8 +++++---
 2 files changed, 6 insertions(+), 4 deletions(-)

Comments

Viresh Kumar March 28, 2022, 3:27 a.m. UTC | #1
On 21-03-22, 09:57, Lukasz Luba wrote:
> The Energy Model can now be artificial, which means the power values
> are mathematically generated to leverage EAS while not expected to be on
> an uniform scale with other devices providing power information. If this
> EM type is in use, the thermal governor IPA should not be allowed to
> operate, since the relation between cooling devices is not properly
> defined. Thus, it might be possible that big GPU has lower power values
> than a Little CPU. To mitigate a misbehaviour of the thermal control
> algorithm, simply do not register the cooling device as IPA's power
> actor.
> 
> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
> ---
>  drivers/thermal/cpufreq_cooling.c | 2 +-
>  drivers/thermal/devfreq_cooling.c | 8 +++++---
>  2 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c
> index 0bfb8eebd126..b8151d95a806 100644
> --- a/drivers/thermal/cpufreq_cooling.c
> +++ b/drivers/thermal/cpufreq_cooling.c
> @@ -328,7 +328,7 @@ static inline bool em_is_sane(struct cpufreq_cooling_device *cpufreq_cdev,
>  	struct cpufreq_policy *policy;
>  	unsigned int nr_levels;
>  
> -	if (!em)
> +	if (!em || em_is_artificial(em))
>  		return false;
>  
>  	policy = cpufreq_cdev->policy;
> diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
> index 4310cb342a9f..b04dcbbf721a 100644
> --- a/drivers/thermal/devfreq_cooling.c
> +++ b/drivers/thermal/devfreq_cooling.c
> @@ -358,6 +358,7 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
>  	struct thermal_cooling_device *cdev;
>  	struct device *dev = df->dev.parent;
>  	struct devfreq_cooling_device *dfc;
> +	struct em_perf_domain *em;
>  	char *name;
>  	int err, num_opps;
>  
> @@ -367,8 +368,9 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
>  
>  	dfc->devfreq = df;
>  
> -	dfc->em_pd = em_pd_get(dev);
> -	if (dfc->em_pd) {
> +	em = em_pd_get(dev);
> +	if (em && !em_is_artificial(em)) {
> +		dfc->em_pd = em;
>  		devfreq_cooling_ops.get_requested_power =
>  			devfreq_cooling_get_requested_power;
>  		devfreq_cooling_ops.state2power = devfreq_cooling_state2power;
> @@ -379,7 +381,7 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
>  		num_opps = em_pd_nr_perf_states(dfc->em_pd);
>  	} else {
>  		/* Backward compatibility for drivers which do not use IPA */
> -		dev_dbg(dev, "missing EM for cooling device\n");
> +		dev_dbg(dev, "missing proper EM for cooling device\n");
>  
>  		num_opps = dev_pm_opp_get_opp_count(dev);

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Lukasz Luba March 29, 2022, 6:37 a.m. UTC | #2
On 3/28/22 04:27, Viresh Kumar wrote:
> On 21-03-22, 09:57, Lukasz Luba wrote:
>> The Energy Model can now be artificial, which means the power values
>> are mathematically generated to leverage EAS while not expected to be on
>> an uniform scale with other devices providing power information. If this
>> EM type is in use, the thermal governor IPA should not be allowed to
>> operate, since the relation between cooling devices is not properly
>> defined. Thus, it might be possible that big GPU has lower power values
>> than a Little CPU. To mitigate a misbehaviour of the thermal control
>> algorithm, simply do not register the cooling device as IPA's power
>> actor.
>>
>> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
>> ---
>>   drivers/thermal/cpufreq_cooling.c | 2 +-
>>   drivers/thermal/devfreq_cooling.c | 8 +++++---
>>   2 files changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c
>> index 0bfb8eebd126..b8151d95a806 100644
>> --- a/drivers/thermal/cpufreq_cooling.c
>> +++ b/drivers/thermal/cpufreq_cooling.c
>> @@ -328,7 +328,7 @@ static inline bool em_is_sane(struct cpufreq_cooling_device *cpufreq_cdev,
>>   	struct cpufreq_policy *policy;
>>   	unsigned int nr_levels;
>>   
>> -	if (!em)
>> +	if (!em || em_is_artificial(em))
>>   		return false;
>>   
>>   	policy = cpufreq_cdev->policy;
>> diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
>> index 4310cb342a9f..b04dcbbf721a 100644
>> --- a/drivers/thermal/devfreq_cooling.c
>> +++ b/drivers/thermal/devfreq_cooling.c
>> @@ -358,6 +358,7 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
>>   	struct thermal_cooling_device *cdev;
>>   	struct device *dev = df->dev.parent;
>>   	struct devfreq_cooling_device *dfc;
>> +	struct em_perf_domain *em;
>>   	char *name;
>>   	int err, num_opps;
>>   
>> @@ -367,8 +368,9 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
>>   
>>   	dfc->devfreq = df;
>>   
>> -	dfc->em_pd = em_pd_get(dev);
>> -	if (dfc->em_pd) {
>> +	em = em_pd_get(dev);
>> +	if (em && !em_is_artificial(em)) {
>> +		dfc->em_pd = em;
>>   		devfreq_cooling_ops.get_requested_power =
>>   			devfreq_cooling_get_requested_power;
>>   		devfreq_cooling_ops.state2power = devfreq_cooling_state2power;
>> @@ -379,7 +381,7 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
>>   		num_opps = em_pd_nr_perf_states(dfc->em_pd);
>>   	} else {
>>   		/* Backward compatibility for drivers which do not use IPA */
>> -		dev_dbg(dev, "missing EM for cooling device\n");
>> +		dev_dbg(dev, "missing proper EM for cooling device\n");
>>   
>>   		num_opps = dev_pm_opp_get_opp_count(dev);
> 
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
> 

Thank you Viresh for the ACK!
diff mbox series

Patch

diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c
index 0bfb8eebd126..b8151d95a806 100644
--- a/drivers/thermal/cpufreq_cooling.c
+++ b/drivers/thermal/cpufreq_cooling.c
@@ -328,7 +328,7 @@  static inline bool em_is_sane(struct cpufreq_cooling_device *cpufreq_cdev,
 	struct cpufreq_policy *policy;
 	unsigned int nr_levels;
 
-	if (!em)
+	if (!em || em_is_artificial(em))
 		return false;
 
 	policy = cpufreq_cdev->policy;
diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
index 4310cb342a9f..b04dcbbf721a 100644
--- a/drivers/thermal/devfreq_cooling.c
+++ b/drivers/thermal/devfreq_cooling.c
@@ -358,6 +358,7 @@  of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
 	struct thermal_cooling_device *cdev;
 	struct device *dev = df->dev.parent;
 	struct devfreq_cooling_device *dfc;
+	struct em_perf_domain *em;
 	char *name;
 	int err, num_opps;
 
@@ -367,8 +368,9 @@  of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
 
 	dfc->devfreq = df;
 
-	dfc->em_pd = em_pd_get(dev);
-	if (dfc->em_pd) {
+	em = em_pd_get(dev);
+	if (em && !em_is_artificial(em)) {
+		dfc->em_pd = em;
 		devfreq_cooling_ops.get_requested_power =
 			devfreq_cooling_get_requested_power;
 		devfreq_cooling_ops.state2power = devfreq_cooling_state2power;
@@ -379,7 +381,7 @@  of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
 		num_opps = em_pd_nr_perf_states(dfc->em_pd);
 	} else {
 		/* Backward compatibility for drivers which do not use IPA */
-		dev_dbg(dev, "missing EM for cooling device\n");
+		dev_dbg(dev, "missing proper EM for cooling device\n");
 
 		num_opps = dev_pm_opp_get_opp_count(dev);