[PATCH v1 1/2] PM: devfreq: fix typo in DFSO_DOWNDIFFERENTIAL macro name

[PATCH v1 1/2] PM: devfreq: fix typo in DFSO_DOWNDIFFERENTIAL macro name

[Riwen Lu]

Correct the spelling error in the DFSO_DOWNDIFFERENTIAL macro
definition and update the corresponding variable assignment.

The macro was previously misspelled as DFSO_DOWNDIFFERENCTIAL.
This change ensures consistent and correct spelling throughout
the simpleondemand governor implementation.

Signed-off-by: Riwen Lu <luriwen@kylinos.cn>
---
 drivers/devfreq/governor_simpleondemand.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
index c23435736367..b4d7be766f33 100644
--- a/drivers/devfreq/governor_simpleondemand.c
+++ b/drivers/devfreq/governor_simpleondemand.c
@@ -14,7 +14,7 @@
 
 /* Default constants for DevFreq-Simple-Ondemand (DFSO) */
 #define DFSO_UPTHRESHOLD	(90)
-#define DFSO_DOWNDIFFERENCTIAL	(5)
+#define DFSO_DOWNDIFFERENTIAL	(5)
 static int devfreq_simple_ondemand_func(struct devfreq *df,
 					unsigned long *freq)
 {
@@ -22,7 +22,7 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
 	struct devfreq_dev_status *stat;
 	unsigned long long a, b;
 	unsigned int dfso_upthreshold = DFSO_UPTHRESHOLD;
-	unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENCTIAL;
+	unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENTIAL;
 	struct devfreq_simple_ondemand_data *data = df->data;
 
 	err = devfreq_update_stats(df);
-- 
2.25.1

[PATCH v1 2/2] PM: devfreq: handle invalid parameters gracefully in simpleondemand

[Riwen Lu]

Instead of returning -EINVAL when upthreshold > 100 or upthreshold <
downdifferential, fall back to default threshold values to ensure the
governor continues functioning.

Additionally, the validation is now scoped to the if (data) block,
preventing unnecessary checks when no user data is provided, while the
fallback mechanism ensures reliability with invalid configurations.

Signed-off-by: Riwen Lu <luriwen@kylinos.cn>
---
 drivers/devfreq/governor_simpleondemand.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
index b4d7be766f33..7205891d2ec6 100644
--- a/drivers/devfreq/governor_simpleondemand.c
+++ b/drivers/devfreq/governor_simpleondemand.c
@@ -36,10 +36,15 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
 			dfso_upthreshold = data->upthreshold;
 		if (data->downdifferential)
 			dfso_downdifferential = data->downdifferential;
+
+		if (dfso_upthreshold > 100 ||
+		    dfso_upthreshold < dfso_downdifferential) {
+			dfso_upthreshold = DFSO_UPTHRESHOLD;
+			dfso_downdifferential = DFSO_DOWNDIFFERENTIAL;
+			pr_debug("Invalid thresholds, using defaults: up = %u, down = %u\n",
+				dfso_upthreshold, dfso_downdifferential);
+		}
 	}
-	if (dfso_upthreshold > 100 ||
-	    dfso_upthreshold < dfso_downdifferential)
-		return -EINVAL;
 
 	/* Assume MAX if it is going to be divided by zero */
 	if (stat->total_time == 0) {
-- 
2.25.1

Re: [PATCH v1 1/2] PM: devfreq: fix typo in DFSO_DOWNDIFFERENTIAL macro name

[Chanwoo Choi]

25. 11. 18. 12:23에 Riwen Lu 이(가) 쓴 글:
> Correct the spelling error in the DFSO_DOWNDIFFERENTIAL macro
> definition and update the corresponding variable assignment.
> 
> The macro was previously misspelled as DFSO_DOWNDIFFERENCTIAL.
> This change ensures consistent and correct spelling throughout
> the simpleondemand governor implementation.
> 
> Signed-off-by: Riwen Lu <luriwen@kylinos.cn>
> ---
>  drivers/devfreq/governor_simpleondemand.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
> index c23435736367..b4d7be766f33 100644
> --- a/drivers/devfreq/governor_simpleondemand.c
> +++ b/drivers/devfreq/governor_simpleondemand.c
> @@ -14,7 +14,7 @@
>  
>  /* Default constants for DevFreq-Simple-Ondemand (DFSO) */
>  #define DFSO_UPTHRESHOLD	(90)
> -#define DFSO_DOWNDIFFERENCTIAL	(5)
> +#define DFSO_DOWNDIFFERENTIAL	(5)
>  static int devfreq_simple_ondemand_func(struct devfreq *df,
>  					unsigned long *freq)
>  {
> @@ -22,7 +22,7 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
>  	struct devfreq_dev_status *stat;
>  	unsigned long long a, b;
>  	unsigned int dfso_upthreshold = DFSO_UPTHRESHOLD;
> -	unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENCTIAL;
> +	unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENTIAL;
>  	struct devfreq_simple_ondemand_data *data = df->data;
>  
>  	err = devfreq_update_stats(df);

Applied it. Thanks.

-- 
Best Regards,
Samsung Electronics
Chanwoo Choi

Re: [PATCH v1 2/2] PM: devfreq: handle invalid parameters gracefully in simpleondemand

[Chanwoo Choi]

25. 11. 18. 12:23에 Riwen Lu 이(가) 쓴 글:
> Instead of returning -EINVAL when upthreshold > 100 or upthreshold <
> downdifferential, fall back to default threshold values to ensure the
> governor continues functioning.
> 
> Additionally, the validation is now scoped to the if (data) block,
> preventing unnecessary checks when no user data is provided, while the
> fallback mechanism ensures reliability with invalid configurations.
> 
> Signed-off-by: Riwen Lu <luriwen@kylinos.cn>
> ---
>  drivers/devfreq/governor_simpleondemand.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
> index b4d7be766f33..7205891d2ec6 100644
> --- a/drivers/devfreq/governor_simpleondemand.c
> +++ b/drivers/devfreq/governor_simpleondemand.c
> @@ -36,10 +36,15 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
>  			dfso_upthreshold = data->upthreshold;
>  		if (data->downdifferential)
>  			dfso_downdifferential = data->downdifferential;
> +
> +		if (dfso_upthreshold > 100 ||
> +		    dfso_upthreshold < dfso_downdifferential) {
> +			dfso_upthreshold = DFSO_UPTHRESHOLD;
> +			dfso_downdifferential = DFSO_DOWNDIFFERENTIAL;
> +			pr_debug("Invalid thresholds, using defaults: up = %u, down = %u\n",
> +				dfso_upthreshold, dfso_downdifferential);
> +		}
>  	}
> -	if (dfso_upthreshold > 100 ||
> -	    dfso_upthreshold < dfso_downdifferential)
> -		return -EINVAL;
>  
>  	/* Assume MAX if it is going to be divided by zero */
>  	if (stat->total_time == 0) {

If there are wrong initialization of devfreq_simple_ondemand,
it should point out what is wrong because it makes some confusion if there are no error.


-- 
Best Regards,
Samsung Electronics
Chanwoo Choi

Re: [PATCH v1 2/2] PM: devfreq: handle invalid parameters gracefully in simpleondemand

[luriwen]

在 2025/11/23 23:24, Chanwoo Choi 写道:
> 25. 11. 18. 12:23에 Riwen Lu 이(가) 쓴 글:
>> Instead of returning -EINVAL when upthreshold > 100 or upthreshold <
>> downdifferential, fall back to default threshold values to ensure the
>> governor continues functioning.
>>
>> Additionally, the validation is now scoped to the if (data) block,
>> preventing unnecessary checks when no user data is provided, while the
>> fallback mechanism ensures reliability with invalid configurations.
>>
>> Signed-off-by: Riwen Lu <luriwen@kylinos.cn>
>> ---
>>   drivers/devfreq/governor_simpleondemand.c | 11 ++++++++---
>>   1 file changed, 8 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
>> index b4d7be766f33..7205891d2ec6 100644
>> --- a/drivers/devfreq/governor_simpleondemand.c
>> +++ b/drivers/devfreq/governor_simpleondemand.c
>> @@ -36,10 +36,15 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
>>   			dfso_upthreshold = data->upthreshold;
>>   		if (data->downdifferential)
>>   			dfso_downdifferential = data->downdifferential;
>> +
>> +		if (dfso_upthreshold > 100 ||
>> +		    dfso_upthreshold < dfso_downdifferential) {
>> +			dfso_upthreshold = DFSO_UPTHRESHOLD;
>> +			dfso_downdifferential = DFSO_DOWNDIFFERENTIAL;
>> +			pr_debug("Invalid thresholds, using defaults: up = %u, down = %u\n",
>> +				dfso_upthreshold, dfso_downdifferential);
>> +		}
>>   	}
>> -	if (dfso_upthreshold > 100 ||
>> -	    dfso_upthreshold < dfso_downdifferential)
>> -		return -EINVAL;
>>   
>>   	/* Assume MAX if it is going to be divided by zero */
>>   	if (stat->total_time == 0) {
> If there are wrong initialization of devfreq_simple_ondemand,
> it should point out what is wrong because it makes some confusion if there are no error.
>
>
The original intention behind falling back to default values was to ensure the governor remains functional even with invalid configurations. However, I agree that silently using defaults could hide configuration issues from users.

I'd like to keep fallback but add explicit warning or error.

```c

if (dfso_upthreshold > 100 ||
     dfso_upthreshold < dfso_downdifferential) {
         pr_warn("Invalid thresholds (up = %u, down = %u), using 
defaults: up = %u, down = %u\n",
                 dfso_upthreshold, dfso_downdifferential,
                 DFSO_UPTHRESHOLD, DFSO_DOWNDIFFERENTIAL);
         dfso_upthreshold = DFSO_UPTHRESHOLD;
         dfso_downdifferential = DFSO_DOWNDIFFERENTIAL;
}

--

Best Regards,

Riwen Lu