linux-kernel - Re: [PATCH v2 1/2] input: misc: pwm-vibra: Prevent unbalanced regulator

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Date:   Sat, 9 Feb 2019 09:13:03 -0800
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     Paweł Chmiel <pawel.mikolaj.chmiel@...il.com>
Cc:     linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
        Jonathan Bakker <xc-racer2@...e.ca>
Subject: Re: [PATCH v2 1/2] input: misc: pwm-vibra: Prevent unbalanced
 regulator

On Thu, Jan 24, 2019 at 09:27:31PM +0100, Paweł Chmiel wrote:
> From: Jonathan Bakker <xc-racer2@...e.ca>
> 
> pwm_vibrator_stop disables the regulator, but it can be called from
> multiple places, even when the regulator is already disabled. Fix this
> by using regulator_is_enabled check when starting and stopping device.
> 
> Signed-off-by: Jonathan Bakker <xc-racer2@...e.ca>
> Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@...il.com>

Applied, thank you.

> ---
> Changes from v1:
>   - Rather than using regulator_is_enabled api, use local flag for
>     checking if regulator is enabled
> ---
>  drivers/input/misc/pwm-vibra.c | 17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/input/misc/pwm-vibra.c b/drivers/input/misc/pwm-vibra.c
> index 55da191ae550..9df87431d7d4 100644
> --- a/drivers/input/misc/pwm-vibra.c
> +++ b/drivers/input/misc/pwm-vibra.c
> @@ -34,6 +34,7 @@ struct pwm_vibrator {
>  	struct work_struct play_work;
>  	u16 level;
>  	u32 direction_duty_cycle;
> +	bool vcc_on;
>  };
>  
>  static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
> @@ -42,10 +43,13 @@ static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
>  	struct pwm_state state;
>  	int err;
>  
> -	err = regulator_enable(vibrator->vcc);
> -	if (err) {
> -		dev_err(pdev, "failed to enable regulator: %d", err);
> -		return err;
> +	if (!vibrator->vcc_on) {
> +		err = regulator_enable(vibrator->vcc);
> +		if (err) {
> +			dev_err(pdev, "failed to enable regulator: %d", err);
> +			return err;
> +		}
> +		vibrator->vcc_on = true;
>  	}
>  
>  	pwm_get_state(vibrator->pwm, &state);
> @@ -76,7 +80,10 @@ static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
>  
>  static void pwm_vibrator_stop(struct pwm_vibrator *vibrator)
>  {
> -	regulator_disable(vibrator->vcc);
> +	if (vibrator->vcc_on) {
> +		regulator_disable(vibrator->vcc);
> +		vibrator->vcc_on = false;
> +	}
>  
>  	if (vibrator->pwm_dir)
>  		pwm_disable(vibrator->pwm_dir);
> -- 
> 2.17.1
> 

-- 
Dmitry