From 4c7b8ca1ae5ed9e27014732c8a918ba11a86cf09 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Wed, 8 Feb 2017 14:07:42 -0800 Subject: [PATCH] hwmon: (it87) Do not overwrite bit 2..6 of pwm control registers 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. Cc: stable@vger.kernel.org # 4.9+ Signed-off-by: Guenter Roeck --- drivers/hwmon/it87.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-) diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c index 4f3fabc..37acb38 100644 --- a/drivers/hwmon/it87.c +++ b/drivers/hwmon/it87.c @@ -1316,25 +1316,35 @@ static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *attr, 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 */ @@ -1480,7 +1490,8 @@ static ssize_t set_pwm_temp_map(struct device *dev, * 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); -- 2.7.4