From a1ffd3c46267ee5c807acd780e15df9bb692223f Mon Sep 17 00:00:00 2001 From: Vadim Pasternak Date: Sun, 12 Feb 2023 16:57:30 +0200 Subject: [PATCH] hwmon: (mlxreg-fan) Return zero speed for broken fan 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 Link: https://lore.kernel.org/r/20230212145730.24247-1-vadimp@nvidia.com Signed-off-by: Guenter Roeck --- 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 b48bd7c..96017cc 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; -- 2.7.4