| Message ID | 20220523110513.407516-5-alexander.stein@ew.tq-group.com |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | hwmon: pwm-fan: switch regulator dynamically | expand |
On Mon, May 23, 2022 at 01:05:11PM +0200, Alexander Stein wrote: > 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: Alexander Stein <alexander.stein@ew.tq-group.com> For my reference: Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > drivers/hwmon/pwm-fan.c | 23 +++++++++++++++-------- > 1 file changed, 15 insertions(+), 8 deletions(-) > > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c > index 04af24268963..fcc1b7b55a65 100644 > --- a/drivers/hwmon/pwm-fan.c > +++ b/drivers/hwmon/pwm-fan.c > @@ -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; > @@ -400,7 +407,7 @@ 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. > */ > @@ -410,7 +417,7 @@ 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;
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 04af24268963..fcc1b7b55a65 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -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; @@ -400,7 +407,7 @@ 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. */ @@ -410,7 +417,7 @@ 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;
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: Alexander Stein <alexander.stein@ew.tq-group.com> --- drivers/hwmon/pwm-fan.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-)