[PATCH 12/13] backlight: tosa_bl: use devm_ functions

[PATCH 12/13] backlight: tosa_bl: use devm_ functions

[Jingoo Han]

The devm_ functions allocate memory that is released when a driver
detaches. This patch uses devm_kzalloc of these functions.

Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
---
 drivers/video/backlight/tosa_bl.c |   11 +++++------
 1 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/video/backlight/tosa_bl.c b/drivers/video/backlight/tosa_bl.c
index 2b241ab..0d54e60 100644
--- a/drivers/video/backlight/tosa_bl.c
+++ b/drivers/video/backlight/tosa_bl.c
@@ -82,8 +82,11 @@ static int __devinit tosa_bl_probe(struct i2c_client *client,
 		const struct i2c_device_id *id)
 {
 	struct backlight_properties props;
-	struct tosa_bl_data *data = kzalloc(sizeof(struct tosa_bl_data), GFP_KERNEL);
+	struct tosa_bl_data *data;
 	int ret = 0;
+
+	data = devm_kzalloc(&client->dev, sizeof(struct tosa_bl_data),
+				GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
@@ -92,7 +95,7 @@ static int __devinit tosa_bl_probe(struct i2c_client *client,
 	ret = gpio_request(TOSA_GPIO_BL_C20MA, "backlight");
 	if (ret) {
 		dev_dbg(&data->bl->dev, "Unable to request gpio!\n");
-		goto err_gpio_bl;
+		return ret;
 	}
 	ret = gpio_direction_output(TOSA_GPIO_BL_C20MA, 0);
 	if (ret)
@@ -122,8 +125,6 @@ err_reg:
 	data->bl = NULL;
 err_gpio_dir:
 	gpio_free(TOSA_GPIO_BL_C20MA);
-err_gpio_bl:
-	kfree(data);
 	return ret;
 }
 
@@ -136,8 +137,6 @@ static int __devexit tosa_bl_remove(struct i2c_client *client)
 
 	gpio_free(TOSA_GPIO_BL_C20MA);
 
-	kfree(data);
-
 	return 0;
 }
 
-- 
1.7.1

Re: [PATCH 12/13] backlight: tosa_bl: use devm_ functions

[Dmitry Eremin-Solenikov]

On Fri, May 25, 2012 at 6:30 AM, Jingoo Han <jg1.han@samsung.com> wrote:
> The devm_ functions allocate memory that is released when a driver
> detaches. This patch uses devm_kzalloc of these functions.

Strictly speaking I see no point in this changes. There are no
'missing free' problems
in these drivers, the code path is clean enough. Is devm_kzalloc usage some kind
of policy, or it is just a future-proof change?

>
> Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
> Cc: Richard Purdie <rpurdie@rpsys.net>
> Signed-off-by: Jingoo Han <jg1.han@samsung.com>
> ---
>  drivers/video/backlight/tosa_bl.c |   11 +++++------
>  1 files changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/video/backlight/tosa_bl.c b/drivers/video/backlight/tosa_bl.c
> index 2b241ab..0d54e60 100644
> --- a/drivers/video/backlight/tosa_bl.c
> +++ b/drivers/video/backlight/tosa_bl.c
> @@ -82,8 +82,11 @@ static int __devinit tosa_bl_probe(struct i2c_client *client,
>                const struct i2c_device_id *id)
>  {
>        struct backlight_properties props;
> -       struct tosa_bl_data *data = kzalloc(sizeof(struct tosa_bl_data), GFP_KERNEL);
> +       struct tosa_bl_data *data;
>        int ret = 0;
> +
> +       data = devm_kzalloc(&client->dev, sizeof(struct tosa_bl_data),
> +                               GFP_KERNEL);
>        if (!data)
>                return -ENOMEM;
>
> @@ -92,7 +95,7 @@ static int __devinit tosa_bl_probe(struct i2c_client *client,
>        ret = gpio_request(TOSA_GPIO_BL_C20MA, "backlight");
>        if (ret) {
>                dev_dbg(&data->bl->dev, "Unable to request gpio!\n");
> -               goto err_gpio_bl;
> +               return ret;
>        }
>        ret = gpio_direction_output(TOSA_GPIO_BL_C20MA, 0);
>        if (ret)
> @@ -122,8 +125,6 @@ err_reg:
>        data->bl = NULL;
>  err_gpio_dir:
>        gpio_free(TOSA_GPIO_BL_C20MA);
> -err_gpio_bl:
> -       kfree(data);
>        return ret;
>  }
>
> @@ -136,8 +137,6 @@ static int __devexit tosa_bl_remove(struct i2c_client *client)
>
>        gpio_free(TOSA_GPIO_BL_C20MA);
>
> -       kfree(data);
> -
>        return 0;
>  }
>
> --
> 1.7.1
>
>



-- 
With best wishes
Dmitry

Re: [PATCH 12/13] backlight: tosa_bl: use devm_ functions

[Mark Brown]

On Sat, May 26, 2012 at 10:43:07AM +0400, Dmitry Eremin-Solenikov wrote:
> On Fri, May 25, 2012 at 6:30 AM, Jingoo Han <jg1.han@samsung.com> wrote:

> > The devm_ functions allocate memory that is released when a driver
> > detaches. This patch uses devm_kzalloc of these functions.

> Strictly speaking I see no point in this changes. There are no
> 'missing free' problems
> in these drivers, the code path is clean enough. Is devm_kzalloc usage some kind
> of policy, or it is just a future-proof change?

It does provide robustness against future changes and it's also the more
current style; if nothing else it helps anyone who wants to go and audit
for leaks.