diff options
| author | Guenter Roeck <linux@roeck-us.net> | 2021-05-26 08:40:20 -0700 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2021-06-17 04:21:46 -0700 |
| commit | 2013607b85f03ff24a5a19933705905a1b324a31 (patch) | |
| tree | 07f2a2fef95139bd5e97d111cd5caedd3ceb9899 /drivers/hwmon | |
| parent | 148c847c9e5a54b99850617bf9c143af9a344f92 (diff) | |
hwmon: (max31790) Clear fan fault after reporting it
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>
Tested-by: Václav Kubernát <kubernat@cesnet.cz>
Link: https://lore.kernel.org/r/20210526154022.3223012-6-linux@roeck-us.net
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/max31790.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c index 67677c437768..7927468c5271 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); @@ -181,7 +181,21 @@ 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; |