4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guenter Roeck <linux@xxxxxxxxxxxx> commit 4c7b8ca1ae5ed9e27014732c8a918ba11a86cf09 upstream. In IT8620E, after setting pwm control to manual, it was observed that pwm values for fan 4..6 have reversed results (writing 0 results in fans running at full speed, writing 255 results in fans turned off). With the new PWM control, pwm polarity for pwm control 4..6 is specified in its pwm control registers. Those registers are overwritten when setting the pwm mode or the temperature mapping. Do not touch bit 2..6 of pwm control registers on register writes to fix the problem. Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/hwmon/it87.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-) --- a/drivers/hwmon/it87.c +++ b/drivers/hwmon/it87.c @@ -1300,25 +1300,35 @@ static ssize_t set_pwm_enable(struct dev it87_write_value(data, IT87_REG_FAN_MAIN_CTRL, data->fan_main_ctrl); } else { + u8 ctrl; + /* No on/off mode, set maximum pwm value */ data->pwm_duty[nr] = pwm_to_reg(data, 0xff); it87_write_value(data, IT87_REG_PWM_DUTY[nr], data->pwm_duty[nr]); /* and set manual mode */ - data->pwm_ctrl[nr] = has_newer_autopwm(data) ? - data->pwm_temp_map[nr] : - data->pwm_duty[nr]; - it87_write_value(data, IT87_REG_PWM[nr], - data->pwm_ctrl[nr]); + if (has_newer_autopwm(data)) { + ctrl = (data->pwm_ctrl[nr] & 0x7c) | + data->pwm_temp_map[nr]; + } else { + ctrl = data->pwm_duty[nr]; + } + data->pwm_ctrl[nr] = ctrl; + it87_write_value(data, IT87_REG_PWM[nr], ctrl); } } else { - if (val == 1) /* Manual mode */ - data->pwm_ctrl[nr] = has_newer_autopwm(data) ? - data->pwm_temp_map[nr] : - data->pwm_duty[nr]; - else /* Automatic mode */ - data->pwm_ctrl[nr] = 0x80 | data->pwm_temp_map[nr]; - it87_write_value(data, IT87_REG_PWM[nr], data->pwm_ctrl[nr]); + u8 ctrl; + + if (has_newer_autopwm(data)) { + ctrl = (data->pwm_ctrl[nr] & 0x7c) | + data->pwm_temp_map[nr]; + if (val != 1) + ctrl |= 0x80; + } else { + ctrl = (val == 1 ? data->pwm_duty[nr] : 0x80); + } + data->pwm_ctrl[nr] = ctrl; + it87_write_value(data, IT87_REG_PWM[nr], ctrl); if (data->type != it8603 && nr < 3) { /* set SmartGuardian mode */ @@ -1462,7 +1472,8 @@ static ssize_t set_pwm_temp_map(struct d * otherwise, just store it for later use. */ if (data->pwm_ctrl[nr] & 0x80) { - data->pwm_ctrl[nr] = 0x80 | data->pwm_temp_map[nr]; + data->pwm_ctrl[nr] = (data->pwm_ctrl[nr] & 0xfc) | + data->pwm_temp_map[nr]; it87_write_value(data, IT87_REG_PWM[nr], data->pwm_ctrl[nr]); } mutex_unlock(&data->update_lock);