It was necessary to decouple code handling writing to sysfs from the one responsible for setting PWM of the fan. Due to that, new __set_pwm() method was extracted, which is responsible for only setting new PWM duty cycle. Signed-off-by: Lukasz Majewski <l.majewski@xxxxxxxxxxx> --- drivers/hwmon/pwm-fan.c | 35 ++++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-) diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 1991d903..870e100 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -33,21 +33,15 @@ struct pwm_fan_ctx { unsigned char pwm_value; }; -static ssize_t set_pwm(struct device *dev, struct device_attribute *attr, - const char *buf, size_t count) +static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) { - struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); - unsigned long pwm, duty; - ssize_t ret; - - if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM) - return -EINVAL; - - mutex_lock(&ctx->lock); + unsigned long duty; + int ret; if (ctx->pwm_value == pwm) - goto exit_set_pwm_no_change; + return 0; + mutex_lock(&ctx->lock); if (pwm == 0) { pwm_disable(ctx->pwm); goto exit_set_pwm; @@ -66,13 +60,28 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *attr, exit_set_pwm: ctx->pwm_value = pwm; -exit_set_pwm_no_change: - ret = count; exit_set_pwm_err: mutex_unlock(&ctx->lock); return ret; } +static ssize_t set_pwm(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); + unsigned long pwm; + int ret; + + if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM) + return -EINVAL; + + ret = __set_pwm(ctx, pwm); + if (ret) + return ret; + + return count; +} + static ssize_t show_pwm(struct device *dev, struct device_attribute *attr, char *buf) { -- 2.0.0.rc2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html