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authorDi Shen <di.shen@unisoc.com>2024-01-10 19:55:26 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2024-01-12 15:38:23 +0100
commite95fa7404716f6e25021e66067271a4ad8eb1486 (patch)
tree56c0d47b462f319962fea95f7863082e5c40e77a /drivers/thermal
parentfd881eac3af6c4e36b34ce92d69fb1d7e95f5920 (diff)
thermal: gov_power_allocator: avoid inability to reset a cdev
Commit 0952177f2a1f ("thermal/core/power_allocator: Update once cooling devices when temp is low") adds an update flag to avoid triggering a thermal event when there is no need, and the thermal cdev is updated once when the temperature is low. But when the trips are writable, and switch_on_temp is set to be a higher value, the cooling device state may not be reset to 0, because last_temperature is smaller than switch_on_temp. For example: First: switch_on_temp=70 control_temp=85; Then userspace change the trip_temp: switch_on_temp=45 control_temp=55 cur_temp=54 Then userspace reset the trip_temp: switch_on_temp=70 control_temp=85 cur_temp=57 last_temp=54 At this time, the cooling device state should be reset to 0. However, because cur_temp(57) < switch_on_temp(70) last_temp(54) < switch_on_temp(70) ----> update = false, update is false, the cooling device state can not be reset. Using the observation that tz->passive can also be regarded as the temperature status, set the update flag to the tz->passive value. When the temperature drops below switch_on for the first time, the states of cooling devices can be reset once, and tz->passive is updated to 0. In the next round, because tz->passive is 0, cdev->state will not be updated. By using the tz->passive value as the "update" flag, the issue above can be solved, and the cooling devices can be updated only once when the temperature is low. Fixes: 0952177f2a1f ("thermal/core/power_allocator: Update once cooling devices when temp is low") Cc: 5.13+ <stable@vger.kernel.org> # 5.13+ Suggested-by: Wei Wang <wvw@google.com> Signed-off-by: Di Shen <di.shen@unisoc.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/thermal')
-rw-r--r--drivers/thermal/gov_power_allocator.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c
index 7b6aa265ff6a..81e061f183ad 100644
--- a/drivers/thermal/gov_power_allocator.c
+++ b/drivers/thermal/gov_power_allocator.c
@@ -762,7 +762,7 @@ static int power_allocator_throttle(struct thermal_zone_device *tz,
trip = params->trip_switch_on;
if (trip && tz->temperature < trip->temperature) {
- update = tz->last_temperature >= trip->temperature;
+ update = tz->passive;
tz->passive = 0;
reset_pid_controller(params);
allow_maximum_power(tz, update);