From: Thierry Reding <treding@xxxxxxxxxx> For many setups the bang-bang governor is exactly what we want. Many ARM SoC-based devices use fans to cool down the entire SoC and that works well only with the bang-bang governor because it uses the hysteresis in order to let the fan run for a while to cool the SoC down below the trip point before switching it off again. The step-wise governor will behave strangely in these situations. It doesn't use the hysteresis, so it can lead to situations where the fan is turned on for only a very brief period and then is switched back off, only to get switched back on again very quickly because the SoC hasn't cooled down very much. Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> --- drivers/thermal/Kconfig | 8 ++++++++ drivers/thermal/thermal_core.h | 2 ++ 2 files changed, 10 insertions(+) diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index 4cd7ab707315..19a4b33cb564 100644 --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -130,6 +130,14 @@ config THERMAL_DEFAULT_GOV_POWER_ALLOCATOR system and device power allocation. This governor can only operate on cooling devices that implement the power API. +config THERMAL_DEFAULT_GOV_BANG_BANG + bool "bang_bang" + depends on THERMAL_GOV_BANG_BANG + help + Use the bang_bang governor as default. This throttles the + devices one step at the time, taking into account the trip + point hysteresis. + endchoice config THERMAL_GOV_FAIR_SHARE diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h index 3d4a787c6b28..17c1bbed734d 100644 --- a/drivers/thermal/thermal_core.h +++ b/drivers/thermal/thermal_core.h @@ -23,6 +23,8 @@ #define DEFAULT_THERMAL_GOVERNOR "user_space" #elif defined(CONFIG_THERMAL_DEFAULT_GOV_POWER_ALLOCATOR) #define DEFAULT_THERMAL_GOVERNOR "power_allocator" +#elif defined(CONFIG_THERMAL_DEFAULT_GOV_BANG_BANG) +#define DEFAULT_THERMAL_GOVERNOR "bang_bang" #endif /* Initial state of a cooling device during binding */ -- 2.40.1
