[PATCH] leds: lm3642: use guard to simplify locking

[PATCH] leds: lm3642: use guard to simplify locking

[Richard Lyu]

The mutex_lock()/mutex_unlock() pattern requires explicitly pairing
lock and unlock calls. Use guard(mutex) instead so the lock is
automatically released when the scope exits.

Convert to guard(mutex) in lm3642_torch_brightness_set(),
lm3642_strobe_brightness_set(), and lm3642_indicator_brightness_set().
Add #include <linux/cleanup.h> to support scoped guards.

Signed-off-by: Richard Lyu <richard.lyu@suse.com>
---
 drivers/leds/leds-lm3642.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/leds/leds-lm3642.c b/drivers/leds/leds-lm3642.c
index 61629d5d6703..ee957d4da882 100644
--- a/drivers/leds/leds-lm3642.c
+++ b/drivers/leds/leds-lm3642.c
@@ -12,6 +12,7 @@
 #include <linux/fs.h>
 #include <linux/regmap.h>
 #include <linux/platform_data/leds-lm3642.h>
+#include <linux/cleanup.h>
 
 #define	REG_FILT_TIME			(0x0)
 #define	REG_IVFM_MODE			(0x1)
@@ -202,10 +203,9 @@ static int lm3642_torch_brightness_set(struct led_classdev *cdev,
 	    container_of(cdev, struct lm3642_chip_data, cdev_torch);
 	int ret;
 
-	mutex_lock(&chip->lock);
+	guard(mutex)(&chip->lock);
 	chip->br_torch = brightness;
 	ret = lm3642_control(chip, chip->br_torch, MODES_TORCH);
-	mutex_unlock(&chip->lock);
 	return ret;
 }
 
@@ -249,10 +249,9 @@ static int lm3642_strobe_brightness_set(struct led_classdev *cdev,
 	    container_of(cdev, struct lm3642_chip_data, cdev_flash);
 	int ret;
 
-	mutex_lock(&chip->lock);
+	guard(mutex)(&chip->lock);
 	chip->br_flash = brightness;
 	ret = lm3642_control(chip, chip->br_flash, MODES_FLASH);
-	mutex_unlock(&chip->lock);
 	return ret;
 }
 
@@ -264,10 +263,9 @@ static int lm3642_indicator_brightness_set(struct led_classdev *cdev,
 	    container_of(cdev, struct lm3642_chip_data, cdev_indicator);
 	int ret;
 
-	mutex_lock(&chip->lock);
+	guard(mutex)(&chip->lock);
 	chip->br_indicator = brightness;
 	ret = lm3642_control(chip, chip->br_indicator, MODES_INDIC);
-	mutex_unlock(&chip->lock);
 	return ret;
 }
 
-- 
2.51.0

Re: [PATCH] leds: lm3642: use guard to simplify locking

[Lee Jones]

[Actually Cc:ing the list this time!]

> The mutex_lock()/mutex_unlock() pattern requires explicitly pairing
> lock and unlock calls. Use guard(mutex) instead so the lock is
> automatically released when the scope exits.
> 
> Convert to guard(mutex) in lm3642_torch_brightness_set(),
> lm3642_strobe_brightness_set(), and lm3642_indicator_brightness_set().
> Add #include <linux/cleanup.h> to support scoped guards.
> 
> Signed-off-by: Richard Lyu <richard.lyu@suse.com>
> ---
>  drivers/leds/leds-lm3642.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/leds/leds-lm3642.c b/drivers/leds/leds-lm3642.c
> index 61629d5d6703..ee957d4da882 100644
> --- a/drivers/leds/leds-lm3642.c
> +++ b/drivers/leds/leds-lm3642.c
> @@ -12,6 +12,7 @@
>  #include <linux/fs.h>
>  #include <linux/regmap.h>
>  #include <linux/platform_data/leds-lm3642.h>
> +#include <linux/cleanup.h>

Could you please take this moment to place these in alphabetical order.

Then rebase your patch on top of it please.

>  #define	REG_FILT_TIME			(0x0)
>  #define	REG_IVFM_MODE			(0x1)
> @@ -202,10 +203,9 @@ static int lm3642_torch_brightness_set(struct led_classdev *cdev,
>  	    container_of(cdev, struct lm3642_chip_data, cdev_torch);
>  	int ret;
>  
> -	mutex_lock(&chip->lock);
> +	guard(mutex)(&chip->lock);
>  	chip->br_torch = brightness;
>  	ret = lm3642_control(chip, chip->br_torch, MODES_TORCH);
> -	mutex_unlock(&chip->lock);
>  	return ret;
>  }
>  
> @@ -249,10 +249,9 @@ static int lm3642_strobe_brightness_set(struct led_classdev *cdev,
>  	    container_of(cdev, struct lm3642_chip_data, cdev_flash);
>  	int ret;
>  
> -	mutex_lock(&chip->lock);
> +	guard(mutex)(&chip->lock);
>  	chip->br_flash = brightness;
>  	ret = lm3642_control(chip, chip->br_flash, MODES_FLASH);
> -	mutex_unlock(&chip->lock);
>  	return ret;
>  }
>  
> @@ -264,10 +263,9 @@ static int lm3642_indicator_brightness_set(struct led_classdev *cdev,
>  	    container_of(cdev, struct lm3642_chip_data, cdev_indicator);
>  	int ret;
>  
> -	mutex_lock(&chip->lock);
> +	guard(mutex)(&chip->lock);
>  	chip->br_indicator = brightness;
>  	ret = lm3642_control(chip, chip->br_indicator, MODES_INDIC);
> -	mutex_unlock(&chip->lock);
>  	return ret;
>  }
>  
> -- 
> 2.51.0
> 

-- 
Lee Jones [李琼斯]