Zero fan speed is reported correctly. Tested-by: Václav Kubernát <kubernat@xxxxxxxxx> st 26. 5. 2021 v 17:41 odesílatel Guenter Roeck <linux@xxxxxxxxxxxx> napsal: > > If a fan is not running or not connected, of if fan monitoring is disabled, > the fan count register returns a fixed value of 0xffe0. So far this is then > translated to a RPM value larger than 0. Since this is misleading and does > not really make much sense, report a fan RPM of 0 in this situation. > > Cc: Jan Kundrát <jan.kundrat@xxxxxxxxx> > Cc: Václav Kubernát <kubernat@xxxxxxxxx> > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> > --- > drivers/hwmon/max31790.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c > index 8e4fd9b7c889..91fe419b596c 100644 > --- a/drivers/hwmon/max31790.c > +++ b/drivers/hwmon/max31790.c > @@ -40,6 +40,8 @@ > #define FAN_RPM_MIN 120 > #define FAN_RPM_MAX 7864320 > > +#define FAN_COUNT_REG_MAX 0xffe0 > + > #define RPM_FROM_REG(reg, sr) (((reg) >> 4) ? \ > ((60 * (sr) * 8192) / ((reg) >> 4)) : \ > FAN_RPM_MAX) > @@ -175,7 +177,10 @@ static int max31790_read_fan(struct device *dev, u32 attr, int channel, > return 0; > case hwmon_fan_input: > sr = get_tach_period(data->fan_dynamics[channel % NR_CHANNEL]); > - rpm = RPM_FROM_REG(data->tach[channel], sr); > + if (data->tach[channel] == FAN_COUNT_REG_MAX) > + rpm = 0; > + else > + rpm = RPM_FROM_REG(data->tach[channel], sr); > *val = rpm; > return 0; > case hwmon_fan_target: > -- > 2.25.1 >
