[PATCH v4 03/12] PM / devfreq: Don't adjust to user limits in governors

[Matthias Kaehlcke]

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 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;
 }
 
-- 
2.18.0.rc2.346.g013aa6912e-goog