Re: [PATCH v5 4/6] acerhdf: Use bang-bang thermal governor

Zhang Rui
2014-08-27T07:48:54Z

On Tue, 2014-07-22 at 17:37 +0200, Peter Feuerer wrote:
> acerhdf has been doing an on-off fan control using hysteresis by
> post-manipulating the outcome of thermal subsystem trip point handling.
> This patch enables acerhdf to use the bang-bang governor, which is
> intended for on-off controlled fans.
>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> CC: Zhang Rui <rui.zhang@intel.com>
> Cc: Andreas Mohr <andi@lisas.de>
> Cc: Javi Merino <javi.merino@arm.com>
> Acked-and-tested-by: Borislav Petkov <bp@suse.de>
> Signed-off-by: Peter Feuerer <peter@piie.net>

Peter,

will you take this patch, or do you want me to take this patch along
with Patch 3/6?

thanks,
rui
> ---
> drivers/platform/x86/Kconfig | 3 ++-
> drivers/platform/x86/acerhdf.c | 36 +++++++++++++++++++++++++++++++-----
> 2 files changed, 33 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 172f26c..b5e80dc 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -38,7 +38,8 @@ config ACER_WMI
>
> config ACERHDF
> tristate "Acer Aspire One temperature and fan driver"
> - depends on THERMAL && ACPI
> + select THERMAL_GOV_BANG_BANG
> + depends on ACPI
> ---help---
> This is a driver for Acer Aspire One netbooks. It allows to access
> the temperature sensor and to control the fan.
> diff --git a/drivers/platform/x86/acerhdf.c b/drivers/platform/x86/acerhdf.c
> index f30767f..7fe7dbf 100644
> --- a/drivers/platform/x86/acerhdf.c
> +++ b/drivers/platform/x86/acerhdf.c
> @@ -50,7 +50,7 @@
> */
> #undef START_IN_KERNEL_MODE
>
> -#define DRV_VER "0.5.30"
> +#define DRV_VER "0.7.0"
>
> /*
> * According to the Atom N270 datasheet,
> @@ -258,6 +258,14 @@ static const struct bios_settings_t bios_tbl[] = {
>
> static const struct bios_settings_t *bios_cfg __read_mostly;
>
> +/*
> + * this struct is used to instruct thermal layer to use bang_bang instead of
> + * default governor for acerhdf
> + */
> +static struct thermal_zone_params acerhdf_zone_params = {
> + .governor_name = "bang_bang",
> +};
> +
> static int acerhdf_get_temp(int *temp)
> {
> u8 read_temp;
> @@ -439,6 +447,17 @@ static int acerhdf_get_trip_type(struct thermal_zone_device *thermal, int trip,
> return 0;
> }
>
> +static int acerhdf_get_trip_hyst(struct thermal_zone_device *thermal, int trip,
> + unsigned long *temp)
> +{
> + if (trip != 0)
> + return -EINVAL;
> +
> + *temp = fanon - fanoff;
> +
> + return 0;
> +}
> +
> static int acerhdf_get_trip_temp(struct thermal_zone_device *thermal, int trip,
> unsigned long *temp)
> {
> @@ -463,6 +482,7 @@ static struct thermal_zone_device_ops acerhdf_dev_ops = {
> .get_mode = acerhdf_get_mode,
> .set_mode = acerhdf_set_mode,
> .get_trip_type = acerhdf_get_trip_type,
> + .get_trip_hyst = acerhdf_get_trip_hyst,
> .get_trip_temp = acerhdf_get_trip_temp,
> .get_crit_temp = acerhdf_get_crit_temp,
> };
> @@ -515,9 +535,7 @@ static int acerhdf_set_cur_state(struct thermal_cooling_device *cdev,
> }
>
> if (state == 0) {
> - /* turn fan off only if below fanoff temperature */
> - if ((cur_state == ACERHDF_FAN_AUTO) &&
> - (cur_temp < fanoff))
> + if (cur_state == ACERHDF_FAN_AUTO)
> acerhdf_change_fanstate(ACERHDF_FAN_OFF);
> } else {
> if (cur_state == ACERHDF_FAN_OFF)
> @@ -696,11 +714,19 @@ static int acerhdf_register_thermal(void)
> return -EINVAL;
>
> thz_dev = thermal_zone_device_register("acerhdf", 1, 0, NULL,
> - &acerhdf_dev_ops, NULL, 0,
> + &acerhdf_dev_ops,
> + &acerhdf_zone_params, 0,
> (kernelmode) ? interval*1000 : 0);
> if (IS_ERR(thz_dev))
> return -EINVAL;
>
> + if (strcmp(thz_dev->governor->name,
> + acerhdf_zone_params.governor_name)) {
> + pr_err("Didn't get thermal governor %s, perhaps not compiled into thermal subsystem.\n",
> + acerhdf_zone_params.governor_name);
> + return -EINVAL;
> + }
> +
> return 0;
> }
>