6.12-stable review patch. If anyone has any objections, please let me know.
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From: Vadim Pasternak vadimp@nvidia.com
[ Upstream commit 1180c79fbf36e4c02e76ae4658509523437e52a4 ]
The fans controlled by the driver can get stuck at 0 RPM if they are configured below a 20% duty cycle. The driver tries to avoid this by enforcing a minimum duty cycle of 20%, but this is done after the fans are registered with the thermal subsystem. This is too late as the thermal subsystem can set their current state before the driver is able to enforce the minimum duty cycle.
Fix by setting the minimum duty cycle before registering the fans with the thermal subsystem.
Fixes: d7efb2ebc7b3 ("hwmon: (mlxreg-fan) Extend driver to support multiply cooling devices") Reported-by: Nikolay Aleksandrov razor@blackwall.org Tested-by: Nikolay Aleksandrov razor@blackwall.org Signed-off-by: Ido Schimmel idosch@nvidia.com Signed-off-by: Vadim Pasternak vadimp@nvidia.com Link: https://lore.kernel.org/r/20250730201715.1111133-1-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 | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/hwmon/mlxreg-fan.c b/drivers/hwmon/mlxreg-fan.c index a5f89aab3fb4d..c25a54d5b39ad 100644 --- a/drivers/hwmon/mlxreg-fan.c +++ b/drivers/hwmon/mlxreg-fan.c @@ -561,15 +561,14 @@ static int mlxreg_fan_cooling_config(struct device *dev, struct mlxreg_fan *fan) if (!pwm->connected) continue; pwm->fan = fan; + /* Set minimal PWM speed. */ + pwm->last_hwmon_state = MLXREG_FAN_PWM_DUTY2STATE(MLXREG_FAN_MIN_DUTY); pwm->cdev = devm_thermal_of_cooling_device_register(dev, NULL, mlxreg_fan_name[i], pwm, &mlxreg_fan_cooling_ops); if (IS_ERR(pwm->cdev)) { dev_err(dev, "Failed to register cooling device\n"); return PTR_ERR(pwm->cdev); } - - /* Set minimal PWM speed. */ - pwm->last_hwmon_state = MLXREG_FAN_PWM_DUTY2STATE(MLXREG_FAN_MIN_DUTY); }
return 0;