[PATCH] video: backlight: lcd: fix race condition during register

[PATCH] video: backlight: lcd: fix race condition during register

[Uwe Kleine-König]

From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Once device_register is called for a device its attributes might be
accessed. As the callbacks of a lcd device's attributes make use of the
lcd_ops, the respective member must be setup before calling
device_register.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/video/backlight/lcd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c
index 7de847df224f..4b40c6a4d441 100644
--- a/drivers/video/backlight/lcd.c
+++ b/drivers/video/backlight/lcd.c
@@ -226,6 +226,8 @@ struct lcd_device *lcd_device_register(const char *name, struct device *parent,
 	dev_set_name(&new_ld->dev, "%s", name);
 	dev_set_drvdata(&new_ld->dev, devdata);
 
+	new_ld->ops = ops;
+
 	rc = device_register(&new_ld->dev);
 	if (rc) {
 		put_device(&new_ld->dev);
@@ -238,8 +240,6 @@ struct lcd_device *lcd_device_register(const char *name, struct device *parent,
 		return ERR_PTR(rc);
 	}
 
-	new_ld->ops = ops;
-
 	return new_ld;
 }
 EXPORT_SYMBOL(lcd_device_register);
-- 
2.8.1

Re: [PATCH] video: backlight: lcd: fix race condition during register

[Lee Jones]

On Wed, 06 Jul 2016, Uwe Kleine-König wrote:

> From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> 
> Once device_register is called for a device its attributes might be
> accessed. As the callbacks of a lcd device's attributes make use of the
> lcd_ops, the respective member must be setup before calling
> device_register.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>  drivers/video/backlight/lcd.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Applied, thanks.

> diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c
> index 7de847df224f..4b40c6a4d441 100644
> --- a/drivers/video/backlight/lcd.c
> +++ b/drivers/video/backlight/lcd.c
> @@ -226,6 +226,8 @@ struct lcd_device *lcd_device_register(const char *name, struct device *parent,
>  	dev_set_name(&new_ld->dev, "%s", name);
>  	dev_set_drvdata(&new_ld->dev, devdata);
>  
> +	new_ld->ops = ops;
> +
>  	rc = device_register(&new_ld->dev);
>  	if (rc) {
>  		put_device(&new_ld->dev);
> @@ -238,8 +240,6 @@ struct lcd_device *lcd_device_register(const char *name, struct device *parent,
>  		return ERR_PTR(rc);
>  	}
>  
> -	new_ld->ops = ops;
> -
>  	return new_ld;
>  }
>  EXPORT_SYMBOL(lcd_device_register);

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
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