After running once, the for_each_trip_desc() loop in bang_bang_manage() is pure needless overhead because it is not going to make any changes unless a new cooling device has been bound to one of the trips in the thermal zone or the system is resuming from sleep. For this reason, make bang_bang_manage() set governor_data for the thermal zone and check it upfront to decide whether or not it needs to do anything. However, governor_data needs to be reset in some cases to let bang_bang_manage() know that it should walk the trips again, so add an .update_tz() callback to the governor and make the core additionally invoke it during system resume. To avoid affecting the other users of that callback unnecessarily, add a special notification reason for system resume, THERMAL_TZ_RESUME, and also pass it to __thermal_zone_device_update() called during system resume for consistency. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Acked-by: Peter Kästle <peter@xxxxxxxx> Reviewed-by: Zhang Rui <rui.zhang@xxxxxxxxx> Cc: 6.10+ <stable@xxxxxxxxxxxxxxx> # 6.10+ Link: https://patch.msgid.link/2285575.iZASKD2KPV@xxxxxxxxxxxxx diff --git a/drivers/thermal/gov_bang_bang.c b/drivers/thermal/gov_bang_bang.c index bc55e0698bfa..daed67d19efb 100644 --- a/drivers/thermal/gov_bang_bang.c +++ b/drivers/thermal/gov_bang_bang.c @@ -86,6 +86,10 @@ static void bang_bang_manage(struct thermal_zone_device *tz) const struct thermal_trip_desc *td; struct thermal_instance *instance; + /* If the code below has run already, nothing needs to be done. */ + if (tz->governor_data) + return; + for_each_trip_desc(tz, td) { const struct thermal_trip *trip = &td->trip; @@ -107,11 +111,25 @@ static void bang_bang_manage(struct thermal_zone_device *tz) bang_bang_set_instance_target(instance, 0); } } + + tz->governor_data = (void *)true; +} + +static void bang_bang_update_tz(struct thermal_zone_device *tz, + enum thermal_notify_event reason) +{ + /* + * Let bang_bang_manage() know that it needs to walk trips after binding + * a new cdev and after system resume. + */ + if (reason == THERMAL_TZ_BIND_CDEV || reason == THERMAL_TZ_RESUME) + tz->governor_data = NULL; } static struct thermal_governor thermal_gov_bang_bang = { .name = "bang_bang", .trip_crossed = bang_bang_control, .manage = bang_bang_manage, + .update_tz = bang_bang_update_tz, }; THERMAL_GOVERNOR_DECLARE(thermal_gov_bang_bang); diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index 95c399f94744..e6669aeda1ff 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -1728,7 +1728,8 @@ static void thermal_zone_device_resume(struct work_struct *work) thermal_debug_tz_resume(tz); thermal_zone_device_init(tz); - __thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED); + thermal_governor_update_tz(tz, THERMAL_TZ_RESUME); + __thermal_zone_device_update(tz, THERMAL_TZ_RESUME); complete(&tz->resume); tz->resuming = false; diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 25fbf960b474..b86ddca46b9e 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -55,6 +55,7 @@ enum thermal_notify_event { THERMAL_TZ_BIND_CDEV, /* Cooling dev is bind to the thermal zone */ THERMAL_TZ_UNBIND_CDEV, /* Cooling dev is unbind from the thermal zone */ THERMAL_INSTANCE_WEIGHT_CHANGED, /* Thermal instance weight changed */ + THERMAL_TZ_RESUME, /* Thermal zone is resuming after system sleep */ }; /**
