Re: [PATCH 05/11] PM / devfreq: governors: Return device frequency limits instead of user limits

From: Chanwoo Choi
Date: Mon May 28 2018 - 02:56:50 EST


Hi,

On 2018ë 05ì 26ì 05:30, Matthias Kaehlcke wrote:
> The performance, powersave and simpleondemand governors can return
> df->min/max_freq, which are the user defined frequency limits.
> update_devfreq() already takes care of adjusting the target frequency
> with the user limits if necessary, therefore we can return
> df->scaling_min/max_freq instead, which is the min/max frequency
> supported by the device at a given time (depending on the
> enabled/disabled OPPs)

As you mentioned on the description, update_devfreq() adjusts
the final target frequency. So, actually, there are no any
benefits when changing from max_freq/min_freq to scaling_max/min_freq.

I think that it is not necessary.

>
> Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> ---
> drivers/devfreq/governor_performance.c | 2 +-
> drivers/devfreq/governor_powersave.c | 2 +-
> drivers/devfreq/governor_simpleondemand.c | 6 +++---
> 3 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/devfreq/governor_performance.c b/drivers/devfreq/governor_performance.c
> index 1c990cb45098..a8e3478b3c43 100644
> --- a/drivers/devfreq/governor_performance.c
> +++ b/drivers/devfreq/governor_performance.c
> @@ -20,7 +20,7 @@ static int devfreq_performance_func(struct devfreq *df,
> * target callback should be able to get floor value as
> * said in devfreq.h
> */
> - *freq = df->max_freq;
> + *freq = df->scaling_max_freq;
> return 0;
> }
>
> diff --git a/drivers/devfreq/governor_powersave.c b/drivers/devfreq/governor_powersave.c
> index 0c42f23249ef..8696efd32e5a 100644
> --- a/drivers/devfreq/governor_powersave.c
> +++ b/drivers/devfreq/governor_powersave.c
> @@ -20,7 +20,7 @@ static int devfreq_powersave_func(struct devfreq *df,
> * target callback should be able to get ceiling value as
> * said in devfreq.h
> */
> - *freq = df->min_freq;
> + *freq = df->scaling_min_freq;
> return 0;
> }
>
> diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
> index 3da7554b4837..805fee09c754 100644
> --- a/drivers/devfreq/governor_simpleondemand.c
> +++ b/drivers/devfreq/governor_simpleondemand.c
> @@ -46,7 +46,7 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
>
> /* Assume MAX if it is going to be divided by zero */
> if (stat->total_time == 0) {
> - *freq = df->max_freq;
> + *freq = df->scaling_max_freq;
> return 0;
> }
>
> @@ -59,13 +59,13 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
> /* Set MAX if it's busy enough */
> if (stat->busy_time * 100 >
> stat->total_time * dfso_upthreshold) {
> - *freq = df->max_freq;
> + *freq = df->scaling_max_freq;
> return 0;
> }
>
> /* Set MAX if we do not know the initial frequency */
> if (stat->current_frequency == 0) {
> - *freq = df->max_freq;
> + *freq = df->scaling_max_freq;
> return 0;
> }
>
>


--
Best Regards,
Chanwoo Choi
Samsung Electronics