Re: [PATCH v2 4/4] acerhdf: Use bang-bang thermal governor

Javi Merino
2014-04-29T16:01:05Z

On Tue, Apr 29, 2014 at 10:17:57AM +0100, 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: Zhang Rui <rui.zhang@intel.com>
> Cc: Andreas Mohr <andi@lisas.de>
> Cc: Borislav Petkov <bp@suse.de>
> Signed-off-by: Peter Feuerer <peter@piie.net>
> ---
> drivers/platform/x86/Kconfig | 2 +-
> drivers/platform/x86/acerhdf.c | 48 +++++++++++++++++++++++++++++++++++-------
> 2 files changed, 41 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 27df2c5..0c15d89 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -38,7 +38,7 @@ config ACER_WMI
>
> config ACERHDF
> tristate "Acer Aspire One temperature and fan driver"
> - depends on THERMAL && ACPI
> + depends on ACPI && THERMAL_GOV_BANG_BANG
> ---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 176edbd..f3884f9 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 "0.5.31"
>
> /*
> * According to the Atom N270 datasheet,
> @@ -135,8 +135,8 @@ struct bios_settings_t {
> const char *vendor;
> const char *product;
> const char *version;
> - unsigned char fanreg;
> - unsigned char tempreg;
> + u8 fanreg;
> + u8 tempreg;
> struct fancmd cmd;
> int mcmd_enable;
> };
> @@ -259,6 +259,17 @@ 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",
> + .no_hwmon = 0,
> + .num_tbps = 0,
> + .tbp = 0,
> +};

You don't need to initialize statics to 0. checkpatch only considers
it an error if it finds it in a variable, but I think it also applies
to fields in struct.

> +
> static int acerhdf_get_temp(int *temp)
> {
> u8 read_temp;
> @@ -436,6 +447,17 @@ static int acerhdf_get_trip_type(struct thermal_zone_device *thermal, int trip,
> {
> if (trip == 0)
> *type = THERMAL_TRIP_ACTIVE;
> + if (trip == 1)
> + *type = THERMAL_TRIP_CRITICAL;

This looks like an unrelated change that should be on a patch on its
own.

> +
> + return 0;
> +}
> +
> +static int acerhdf_get_trip_hyst(struct thermal_zone_device *thermal, int trip,
> + unsigned long *temp)
> +{
> + if (trip == 0)
> + *temp = fanon - fanoff;
>
> return 0;
> }
> @@ -445,6 +467,8 @@ static int acerhdf_get_trip_temp(struct thermal_zone_device *thermal, int trip,
> {
> if (trip == 0)
> *temp = fanon;
> + else if (trip == 1)
> + *temp = ACERHDF_TEMP_CRIT;
>
> return 0;
> }
> @@ -464,8 +488,10 @@ 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,
> + .notify = NULL,

Same as before, no need to initialize static to NULL.

Cheers,
Javi