linux-kernel - Re: [PATCH] leds: lm3532: Avoid potentially unpaired regulator calls

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <75c6095c-01a0-3a87-acab-d522225f259b@gmail.com>
Date:   Wed, 28 Aug 2019 22:09:12 +0200
From:   Jacek Anaszewski <jacek.anaszewski@...il.com>
To:     Tony Lindgren <tony@...mide.com>
Cc:     Pavel Machek <pavel@....cz>, Dan Murphy <dmurphy@...com>,
        linux-leds@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] leds: lm3532: Avoid potentially unpaired regulator calls

Hi Tony,

Thank you for the patch.

On 8/27/19 11:52 PM, Tony Lindgren wrote:
> We may currently get unpaired regulator calls when configuring the LED
> brightness via sysfs in case of regulator calls producing errors. Let's
> fix this by maintaining local state for enabled.
> 
> Signed-off-by: Tony Lindgren <tony@...mide.com>
> ---
>  drivers/leds/leds-lm3532.c | 26 ++++++++++++++++++++++++--
>  1 file changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/leds/leds-lm3532.c b/drivers/leds/leds-lm3532.c
> --- a/drivers/leds/leds-lm3532.c
> +++ b/drivers/leds/leds-lm3532.c
> @@ -127,6 +127,7 @@ struct lm3532_als_data {
>   * @num_leds - Number of LED strings are supported in this array
>   * @full_scale_current - The full-scale current setting for the current sink.
>   * @led_strings - The LED strings supported in this array
> + * @enabled - Enabled status
>   * @label - LED label
>   */
>  struct lm3532_led {
> @@ -138,6 +139,7 @@ struct lm3532_led {
>  	int ctrl_brt_pointer;
>  	int num_leds;
>  	int full_scale_current;
> +	int enabled:1;
>  	u32 led_strings[LM3532_MAX_CONTROL_BANKS];
>  	char label[LED_MAX_NAME_SIZE];
>  };
> @@ -292,11 +294,15 @@ static int lm3532_get_ramp_index(int ramp_time)
>  				ramp_time);
>  }
>  
> +/* Caller must take care of locking */
>  static int lm3532_led_enable(struct lm3532_led *led_data)
>  {
>  	int ctrl_en_val = BIT(led_data->control_bank);
>  	int ret;
>  
> +	if (led_data->enabled)
> +		return 0;
> +
>  	ret = regmap_update_bits(led_data->priv->regmap, LM3532_REG_ENABLE,
>  					 ctrl_en_val, ctrl_en_val);
>  	if (ret) {
> @@ -304,14 +310,24 @@ static int lm3532_led_enable(struct lm3532_led *led_data)
>  		return ret;
>  	}
>  
> -	return regulator_enable(led_data->priv->regulator);
> +	ret = regulator_enable(led_data->priv->regulator);
> +	if (ret < 0)
> +		return ret;
> +
> +	led_data->enabled = 1;
> +
> +	return 0;
>  }
>  
> +/* Caller must take care of locking */
>  static int lm3532_led_disable(struct lm3532_led *led_data)
>  {
>  	int ctrl_en_val = BIT(led_data->control_bank);
>  	int ret;
>  
> +	if (!led_data->enabled)
> +		return 0;
> +
>  	ret = regmap_update_bits(led_data->priv->regmap, LM3532_REG_ENABLE,
>  					 ctrl_en_val, 0);
>  	if (ret) {
> @@ -319,7 +335,13 @@ static int lm3532_led_disable(struct lm3532_led *led_data)
>  		return ret;
>  	}
>  
> -	return regulator_disable(led_data->priv->regulator);
> +	ret = regulator_disable(led_data->priv->regulator);
> +	if (ret < 0)
> +		return ret;
> +
> +	led_data->enabled = 0;
> +
> +	return 0;
>  }
>  
>  static int lm3532_brightness_set(struct led_classdev *led_cdev,
> 

Applied.

-- 
Best regards,
Jacek Anaszewski