From: Vadim Pasternak vadimp@nvidia.com
[ Upstream commit a1ffd3c46267ee5c807acd780e15df9bb692223f ]
Currently for broken fan driver returns value calculated based on error code (0xFF) in related fan speed register. Thus, for such fan user gets fan{n}_fault to 1 and fan{n}_input with misleading value.
Add check for fan fault prior return speed value and return zero if fault is detected.
Fixes: 65afb4c8e7e4 ("hwmon: (mlxreg-fan) Add support for Mellanox FAN driver") Signed-off-by: Vadim Pasternak vadimp@nvidia.com Link: https://lore.kernel.org/r/20230212145730.24247-1-vadimp@nvidia.com Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwmon/mlxreg-fan.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/hwmon/mlxreg-fan.c b/drivers/hwmon/mlxreg-fan.c index b48bd7c961d66..96017cc8da7ec 100644 --- a/drivers/hwmon/mlxreg-fan.c +++ b/drivers/hwmon/mlxreg-fan.c @@ -155,6 +155,12 @@ mlxreg_fan_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, if (err) return err;
+ if (MLXREG_FAN_GET_FAULT(regval, tacho->mask)) { + /* FAN is broken - return zero for FAN speed. */ + *val = 0; + return 0; + } + *val = MLXREG_FAN_GET_RPM(regval, fan->divider, fan->samples); break;