Re: [PATCH v5 03/12] PM / devfreq: Don't adjust to user limits in governors

From: Chanwoo Choi
Date: Thu Aug 02 2018 - 20:03:40 EST

Hi Matthias,

On 2018ë 08ì 03ì 08:36, Matthias Kaehlcke wrote:
> Hi Chanwoo,
>
> this patch and "PM / devfreq: Fix handling of min/max_freq == 0"
> address issues not directly related with the throttler. It seems it
> could still take a while for the throttler to move forward, do you
> want me to spin out these two patches so that they can get merged
> independently from the rest of the series?

How about resend the devfreq patches(patch1/2/3/4/6) which don't depend on
throttler core with my reviewed tag? Maybe, it is easy to merge them through Myungjoo.

Regards,
Chanwoo Choi

>
> Thanks
>
> Matthias
>
> On Tue, Jul 03, 2018 at 04:46:56PM -0700, Matthias Kaehlcke wrote:
>> Several governors use the user space limits df->min/max_freq to adjust
>> the target frequency. This is not necessary, since update_devfreq()
>> already takes care of this. Instead the governor can request the available
>> min/max frequency by setting the target frequency to DEVFREQ_MIN/MAX_FREQ
>> and let update_devfreq() take care of any adjustments.
>>
>> Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
>> Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx>
>> ---
>> Changes in v5:
>> - none
>>
>> Changes in v4:
>> - added 'Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx>' tag
>>
>> Changes in v3:
>> - none
>>
>> Changes in v2:
>> - squashed "PM / devfreq: Remove redundant frequency adjustment from governors"
>> and "PM / devfreq: governors: Return device frequency limits instead of user
>> limits"
>> - updated subject and commit message
>> - use DEVFREQ_MIN/MAX_FREQ instead of df->scaling_min/max_freq
>> ---
>> drivers/devfreq/governor.h | 3 +++
>> drivers/devfreq/governor_performance.c | 5 +----
>> drivers/devfreq/governor_powersave.c | 2 +-
>> drivers/devfreq/governor_simpleondemand.c | 12 +++---------
>> drivers/devfreq/governor_userspace.c | 16 ++++------------
>> 5 files changed, 12 insertions(+), 26 deletions(-)
>>
>> diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h
>> index cfc50a61a90d..b81700244ce3 100644
>> --- a/drivers/devfreq/governor.h
>> +++ b/drivers/devfreq/governor.h
>> @@ -25,6 +25,9 @@
>> #define DEVFREQ_GOV_SUSPEND 0x4
>> #define DEVFREQ_GOV_RESUME 0x5
>>
>> +#define DEVFREQ_MIN_FREQ 0
>> +#define DEVFREQ_MAX_FREQ ULONG_MAX
>> +
>> /**
>> * struct devfreq_governor - Devfreq policy governor
>> * @node: list node - contains registered devfreq governors
>> diff --git a/drivers/devfreq/governor_performance.c b/drivers/devfreq/governor_performance.c
>> index 4d23ecfbd948..ded429fd51be 100644
>> --- a/drivers/devfreq/governor_performance.c
>> +++ b/drivers/devfreq/governor_performance.c
>> @@ -20,10 +20,7 @@ static int devfreq_performance_func(struct devfreq *df,
>> * target callback should be able to get floor value as
>> * said in devfreq.h
>> */
>> - if (!df->max_freq)
>> - *freq = UINT_MAX;
>> - else
>> - *freq = df->max_freq;
>> + *freq = DEVFREQ_MAX_FREQ;
>> return 0;
>> }
>>
>> diff --git a/drivers/devfreq/governor_powersave.c b/drivers/devfreq/governor_powersave.c
>> index 0c42f23249ef..9e8897f5ac42 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 = DEVFREQ_MIN_FREQ;
>> return 0;
>> }
>>
>> diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
>> index 28e0f2de7100..c0417f0e081e 100644
>> --- a/drivers/devfreq/governor_simpleondemand.c
>> +++ b/drivers/devfreq/governor_simpleondemand.c
>> @@ -27,7 +27,6 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
>> unsigned int dfso_upthreshold = DFSO_UPTHRESHOLD;
>> unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENCTIAL;
>> struct devfreq_simple_ondemand_data *data = df->data;
>> - unsigned long max = (df->max_freq) ? df->max_freq : UINT_MAX;
>>
>> err = devfreq_update_stats(df);
>> if (err)
>> @@ -47,7 +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 = max;
>> + *freq = DEVFREQ_MAX_FREQ;
>> return 0;
>> }
>>
>> @@ -60,13 +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 = max;
>> + *freq = DEVFREQ_MAX_FREQ;
>> return 0;
>> }
>>
>> /* Set MAX if we do not know the initial frequency */
>> if (stat->current_frequency == 0) {
>> - *freq = max;
>> + *freq = DEVFREQ_MAX_FREQ;
>> return 0;
>> }
>>
>> @@ -85,11 +84,6 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
>> b = div_u64(b, (dfso_upthreshold - dfso_downdifferential / 2));
>> *freq = (unsigned long) b;
>>
>> - if (df->min_freq && *freq < df->min_freq)
>> - *freq = df->min_freq;
>> - if (df->max_freq && *freq > df->max_freq)
>> - *freq = df->max_freq;
>> -
>> return 0;
>> }
>>
>> diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c
>> index 080607c3f34d..378d84c011df 100644
>> --- a/drivers/devfreq/governor_userspace.c
>> +++ b/drivers/devfreq/governor_userspace.c
>> @@ -26,19 +26,11 @@ static int devfreq_userspace_func(struct devfreq *df, unsigned long *freq)
>> {
>> struct userspace_data *data = df->data;
>>
>> - if (data->valid) {
>> - unsigned long adjusted_freq = data->user_frequency;
>> -
>> - if (df->max_freq && adjusted_freq > df->max_freq)
>> - adjusted_freq = df->max_freq;
>> -
>> - if (df->min_freq && adjusted_freq < df->min_freq)
>> - adjusted_freq = df->min_freq;
>> -
>> - *freq = adjusted_freq;
>> - } else {
>> + if (data->valid)
>> + *freq = data->user_frequency;
>> + else
>> *freq = df->previous_freq; /* No user freq specified yet */
>> - }
>> +
>> return 0;
>> }
>>
>
>