| Message ID | 20210526154022.3223012-6-linux@roeck-us.net (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | hwmon: (max31790) Fixes and improvements | expand |
Fan fault reading/clearing works fine. Tested-by: Václav Kubernát <kubernat@cesnet.cz> st 26. 5. 2021 v 17:41 odesílatel Guenter Roeck <linux@roeck-us.net> napsal: > > Fault bits in MAX31790 are sticky and have to be cleared explicitly. > A write operation into either the 'Target Duty Cycle' register or the > 'Target Count' register is necessary to clear a fault. > > At the same time, we can never clear cached fault status values before > reading them because the companion fault status for any given fan is > cleared as well when clearing a fault. > > Cc: Jan Kundrát <jan.kundrat@cesnet.cz> > Cc: Václav Kubernát <kubernat@cesnet.cz> > Signed-off-by: Guenter Roeck <linux@roeck-us.net> > --- > drivers/hwmon/max31790.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c > index 19651feb40fb..8e4fd9b7c889 100644 > --- a/drivers/hwmon/max31790.c > +++ b/drivers/hwmon/max31790.c > @@ -80,7 +80,7 @@ static struct max31790_data *max31790_update_device(struct device *dev) > MAX31790_REG_FAN_FAULT_STATUS1); > if (rv < 0) > goto abort; > - data->fault_status = rv & 0x3F; > + data->fault_status |= rv & 0x3F; > > rv = i2c_smbus_read_byte_data(client, > MAX31790_REG_FAN_FAULT_STATUS2); > @@ -184,7 +184,21 @@ static int max31790_read_fan(struct device *dev, u32 attr, int channel, > *val = rpm; > return 0; > case hwmon_fan_fault: > + mutex_lock(&data->update_lock); > *val = !!(data->fault_status & (1 << channel)); > + data->fault_status &= ~(1 << channel); > + /* > + * If a fault bit is set, we need to write into one of the fan > + * configuration registers to clear it. Note that this also > + * clears the fault for the companion channel if enabled. > + */ > + if (*val) { > + int reg = MAX31790_REG_TARGET_COUNT(channel % NR_CHANNEL); > + > + i2c_smbus_write_byte_data(data->client, reg, > + data->target_count[channel % NR_CHANNEL] >> 8); > + } > + mutex_unlock(&data->update_lock); > return 0; > default: > return -EOPNOTSUPP; > -- > 2.25.1 >
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c index 19651feb40fb..8e4fd9b7c889 100644 --- a/drivers/hwmon/max31790.c +++ b/drivers/hwmon/max31790.c @@ -80,7 +80,7 @@ static struct max31790_data *max31790_update_device(struct device *dev) MAX31790_REG_FAN_FAULT_STATUS1); if (rv < 0) goto abort; - data->fault_status = rv & 0x3F; + data->fault_status |= rv & 0x3F; rv = i2c_smbus_read_byte_data(client, MAX31790_REG_FAN_FAULT_STATUS2); @@ -184,7 +184,21 @@ static int max31790_read_fan(struct device *dev, u32 attr, int channel, *val = rpm; return 0; case hwmon_fan_fault: + mutex_lock(&data->update_lock); *val = !!(data->fault_status & (1 << channel)); + data->fault_status &= ~(1 << channel); + /* + * If a fault bit is set, we need to write into one of the fan + * configuration registers to clear it. Note that this also + * clears the fault for the companion channel if enabled. + */ + if (*val) { + int reg = MAX31790_REG_TARGET_COUNT(channel % NR_CHANNEL); + + i2c_smbus_write_byte_data(data->client, reg, + data->target_count[channel % NR_CHANNEL] >> 8); + } + mutex_unlock(&data->update_lock); return 0; default: return -EOPNOTSUPP;
Fault bits in MAX31790 are sticky and have to be cleared explicitly. A write operation into either the 'Target Duty Cycle' register or the 'Target Count' register is necessary to clear a fault. At the same time, we can never clear cached fault status values before reading them because the companion fault status for any given fan is cleared as well when clearing a fault. Cc: Jan Kundrát <jan.kundrat@cesnet.cz> Cc: Václav Kubernát <kubernat@cesnet.cz> Signed-off-by: Guenter Roeck <linux@roeck-us.net> --- drivers/hwmon/max31790.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)