Commit 9db6e7f5 authored by Alexander Stein's avatar Alexander Stein Committed by Guenter Roeck
Browse files

hwmon: (pwm-fan) split __set_pwm into locked/unlocked functions 



Regular calls to set_pwm don't hold the mutex, but the upcoming
update_enable support needs to call set_pwm with the mutex being held.
So provide the previous behavior in set_pwm (handling the lock), while
adding __set_pwm which assumes the lock being held.

Signed-off-by: default avatarAlexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220914153137.613982-5-alexander.stein@ew.tq-group.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 9bf3aa60

drivers/hwmon/pwm-fan.c

+15 −8
Original line number Diff line number Diff line
@@ -152,14 +152,12 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) 
	unsigned long period;

	int ret = 0;



	mutex_lock(&ctx->lock);



	if (pwm > 0) {

		period = state->period;

		state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);

		ret = pwm_apply_state(ctx->pwm, state);

		if (ret)

			goto exit_set_pwm_err;

			return ret;

		ret = pwm_fan_power_on(ctx);

	} else {

		ret = pwm_fan_power_off(ctx);
@@ -167,8 +165,17 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) 
	if (!ret)

		ctx->pwm_value = pwm;



exit_set_pwm_err:

	return ret;

}



static int set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)

{

	int ret;



	mutex_lock(&ctx->lock);

	ret = __set_pwm(ctx, pwm);

	mutex_unlock(&ctx->lock);



	return ret;

}
@@ -192,7 +199,7 @@ static int pwm_fan_write(struct device *dev, enum hwmon_sensor_types type, 
	if (val < 0 || val > MAX_PWM)

		return -EINVAL;



	ret = __set_pwm(ctx, val);

	ret = set_pwm(ctx, val);

	if (ret)

		return ret;
@@ -280,7 +287,7 @@ pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state) 
	if (state == ctx->pwm_fan_state)

		return 0;



	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);

	ret = set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);

	if (ret) {

		dev_err(&cdev->device, "Cannot set pwm!\n");

		return ret;
@@ -398,7 +405,7 @@ static int pwm_fan_probe(struct platform_device *pdev) 
	pwm_init_state(ctx->pwm, &ctx->pwm_state);



	/*

	 * __set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned

	 * set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned

	 * long. Check this here to prevent the fan running at a too low

	 * frequency.

	 */
@@ -408,7 +415,7 @@ static int pwm_fan_probe(struct platform_device *pdev) 
	}



	/* Set duty cycle to maximum allowed and enable PWM output */

	ret = __set_pwm(ctx, MAX_PWM);

	ret = set_pwm(ctx, MAX_PWM);

	if (ret) {

		dev_err(dev, "Failed to configure PWM: %d\n", ret);

		return ret;