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From:   Thara Gopinath <thara.gopinath@linaro.org>
To:     daniel.lezcano@linaro.org, rui.zhang@intel.com, robh+dt@kernel.org
Cc:     linux-pm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [RFC PATCH 4/4] thermal: Modify thermal governors to do nothing for "cold" trip points
Date:   Fri, 10 Jul 2020 09:51:54 -0400
Message-Id: <20200710135154.181454-5-thara.gopinath@linaro.org>
In-Reply-To: <20200710135154.181454-1-thara.gopinath@linaro.org>
References: <20200710135154.181454-1-thara.gopinath@linaro.org>
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For now, thermal governors do not support monitoring of falling
temperature. Hence, in case of calls to the governor for trip points marked
as cold, return doing nothing.

Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
---
 drivers/thermal/gov_bang_bang.c       | 8 ++++++++
 drivers/thermal/gov_fair_share.c      | 8 ++++++++
 drivers/thermal/gov_power_allocator.c | 8 ++++++++
 drivers/thermal/gov_step_wise.c       | 8 ++++++++
 4 files changed, 32 insertions(+)

diff --git a/drivers/thermal/gov_bang_bang.c b/drivers/thermal/gov_bang_bang.c
index 991a1c54296d..8324d13de1e7 100644
--- a/drivers/thermal/gov_bang_bang.c
+++ b/drivers/thermal/gov_bang_bang.c
@@ -99,6 +99,14 @@ static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip)
 static int bang_bang_control(struct thermal_zone_device *tz, int trip)
 {
 	struct thermal_instance *instance;
+	enum thermal_trip_type trip_type;
+
+	/* Return doing nothing in case of cold trip point */
+	if (trip != THERMAL_TRIPS_NONE) {
+		tz->ops->get_trip_type(tz, trip, &trip_type);
+		if (trip_type == THERMAL_TRIP_COLD)
+			return 0;
+	}
 
 	thermal_zone_trip_update(tz, trip);
 
diff --git a/drivers/thermal/gov_fair_share.c b/drivers/thermal/gov_fair_share.c
index aaa07180ab48..c0adce525faa 100644
--- a/drivers/thermal/gov_fair_share.c
+++ b/drivers/thermal/gov_fair_share.c
@@ -81,6 +81,14 @@ static int fair_share_throttle(struct thermal_zone_device *tz, int trip)
 	int total_weight = 0;
 	int total_instance = 0;
 	int cur_trip_level = get_trip_level(tz);
+	enum thermal_trip_type trip_type;
+
+	/* Return doing nothing in case of cold trip point */
+	if (trip != THERMAL_TRIPS_NONE) {
+		tz->ops->get_trip_type(tz, trip, &trip_type);
+		if (trip_type == THERMAL_TRIP_COLD)
+			return 0;
+	}
 
 	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
 		if (instance->trip != trip)
diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c
index 44636475b2a3..2644ad4d4032 100644
--- a/drivers/thermal/gov_power_allocator.c
+++ b/drivers/thermal/gov_power_allocator.c
@@ -613,8 +613,16 @@ static int power_allocator_throttle(struct thermal_zone_device *tz, int trip)
 {
 	int ret;
 	int switch_on_temp, control_temp;
+	enum thermal_trip_type trip_type;
 	struct power_allocator_params *params = tz->governor_data;
 
+	/* Return doing nothing in case of cold trip point */
+	if (trip != THERMAL_TRIPS_NONE) {
+		tz->ops->get_trip_type(tz, trip, &trip_type);
+		if (trip_type == THERMAL_TRIP_COLD)
+			return 0;
+	}
+
 	/*
 	 * We get called for every trip point but we only need to do
 	 * our calculations once
diff --git a/drivers/thermal/gov_step_wise.c b/drivers/thermal/gov_step_wise.c
index 2ae7198d3067..009aefda0441 100644
--- a/drivers/thermal/gov_step_wise.c
+++ b/drivers/thermal/gov_step_wise.c
@@ -186,6 +186,14 @@ static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip)
 static int step_wise_throttle(struct thermal_zone_device *tz, int trip)
 {
 	struct thermal_instance *instance;
+	enum thermal_trip_type trip_type;
+
+	/* For now, return doing nothing in case of cold trip point */
+	if (trip != THERMAL_TRIPS_NONE) {
+		tz->ops->get_trip_type(tz, trip, &trip_type);
+		if (trip_type == THERMAL_TRIP_COLD)
+			return 0;
+	}
 
 	thermal_zone_trip_update(tz, trip);
 
-- 
2.25.1