diff options
| -rw-r--r-- | drivers/acpi/fan.h | 33 | ||||
| -rw-r--r-- | drivers/acpi/fan_hwmon.c | 10 |
2 files changed, 36 insertions, 7 deletions
diff --git a/drivers/acpi/fan.h b/drivers/acpi/fan.h index bedbab0e8e4e..0d73433c3889 100644 --- a/drivers/acpi/fan.h +++ b/drivers/acpi/fan.h @@ -11,6 +11,7 @@ #define _ACPI_FAN_H_ #include <linux/kconfig.h> +#include <linux/limits.h> #define ACPI_FAN_DEVICE_IDS \ {"INT3404", }, /* Fan */ \ @@ -60,6 +61,38 @@ struct acpi_fan { struct device_attribute fine_grain_control; }; +/** + * acpi_fan_speed_valid - Check if fan speed value is valid + * @speeed: Speed value returned by the ACPI firmware + * + * Check if the fan speed value returned by the ACPI firmware is valid. This function is + * necessary as ACPI firmware implementations can return 0xFFFFFFFF to signal that the + * ACPI fan does not support speed reporting. Additionally, some buggy ACPI firmware + * implementations return a value larger than the 32-bit integer value defined by + * the ACPI specification when using placeholder values. Such invalid values are also + * detected by this function. + * + * Returns: True if the fan speed value is valid, false otherwise. + */ +static inline bool acpi_fan_speed_valid(u64 speed) +{ + return speed < U32_MAX; +} + +/** + * acpi_fan_power_valid - Check if fan power value is valid + * @power: Power value returned by the ACPI firmware + * + * Check if the fan power value returned by the ACPI firmware is valid. + * See acpi_fan_speed_valid() for details. + * + * Returns: True if the fan power value is valid, false otherwise. + */ +static inline bool acpi_fan_power_valid(u64 power) +{ + return power < U32_MAX; +} + int acpi_fan_get_fst(acpi_handle handle, struct acpi_fan_fst *fst); int acpi_fan_create_attributes(struct acpi_device *device); void acpi_fan_delete_attributes(struct acpi_device *device); diff --git a/drivers/acpi/fan_hwmon.c b/drivers/acpi/fan_hwmon.c index 4b2c2007f2d7..47a02ef5a606 100644 --- a/drivers/acpi/fan_hwmon.c +++ b/drivers/acpi/fan_hwmon.c @@ -15,10 +15,6 @@ #include "fan.h" -/* Returned when the ACPI fan does not support speed reporting */ -#define FAN_SPEED_UNAVAILABLE U32_MAX -#define FAN_POWER_UNAVAILABLE U32_MAX - static struct acpi_fan_fps *acpi_fan_get_current_fps(struct acpi_fan *fan, u64 control) { unsigned int i; @@ -77,7 +73,7 @@ static umode_t acpi_fan_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_ * when the associated attribute should not be created. */ for (i = 0; i < fan->fps_count; i++) { - if (fan->fps[i].power != FAN_POWER_UNAVAILABLE) + if (acpi_fan_power_valid(fan->fps[i].power)) return 0444; } @@ -106,7 +102,7 @@ static int acpi_fan_hwmon_read(struct device *dev, enum hwmon_sensor_types type, case hwmon_fan: switch (attr) { case hwmon_fan_input: - if (fst.speed == FAN_SPEED_UNAVAILABLE) + if (!acpi_fan_speed_valid(fst.speed)) return -ENODEV; if (fst.speed > LONG_MAX) @@ -134,7 +130,7 @@ static int acpi_fan_hwmon_read(struct device *dev, enum hwmon_sensor_types type, if (!fps) return -EIO; - if (fps->power == FAN_POWER_UNAVAILABLE) + if (!acpi_fan_power_valid(fps->power)) return -ENODEV; if (fps->power > LONG_MAX / MICROWATT_PER_MILLIWATT) |