[PATCH] leds-ss4200: fix led_classdev_unregister twice in error handling

[PATCH] leds-ss4200: fix led_classdev_unregister twice in error handling

[Axel Lin]

In current implementation, if device_create_file failed in register_nasgpio_led,
led_classdev_unregister will be executed twice.
( in register_nasgpio_led it calls led_classdev_unregister before return and in nas_gpio_init out_err )

This patch fixes it by only unregistering those that were successfully registered in out_err.
( not including last failed register_nasgpio_led call )

Signed-off-by: Axel Lin <axel.lin@gmail.com>
---
 drivers/leds/leds-ss4200.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/leds/leds-ss4200.c b/drivers/leds/leds-ss4200.c
index 51477ec..a688293 100644
--- a/drivers/leds/leds-ss4200.c
+++ b/drivers/leds/leds-ss4200.c
@@ -534,7 +534,7 @@ static int __init nas_gpio_init(void)
 	set_power_light_amber_noblink();
 	return 0;
 out_err:
-	for (; i >= 0; i--)
+	for (i--; i >= 0; i--)
 		unregister_nasgpio_led(i);
 	pci_unregister_driver(&nas_gpio_pci_driver);
 	return ret;
-- 
1.5.4.3

Re: [PATCH] leds-ss4200: fix led_classdev_unregister twice in error handling

[Dave Hansen]

On Mon, 2010-05-17 at 13:42 +0800, Axel Lin wrote:
> In current implementation, if device_create_file failed in
> register_nasgpio_led,
> led_classdev_unregister will be executed twice.
> ( in register_nasgpio_led it calls led_classdev_unregister before
> return and in nas_gpio_init out_err )
> 
> This patch fixes it by only unregistering those that were successfully
> registered in out_err.
> ( not including last failed register_nasgpio_led call )

Did you actually run into this, or did you find this just auditing code?

> diff --git a/drivers/leds/leds-ss4200.c b/drivers/leds/leds-ss4200.c
> index 51477ec..a688293 100644
> --- a/drivers/leds/leds-ss4200.c
> +++ b/drivers/leds/leds-ss4200.c
> @@ -534,7 +534,7 @@ static int __init nas_gpio_init(void)
>  	set_power_light_amber_noblink();
>  	return 0;
>  out_err:
> -	for (; i >= 0; i--)
> +	for (i--; i >= 0; i--)
>  		unregister_nasgpio_led(i);
>  	pci_unregister_driver(&nas_gpio_pci_driver);
>  	return ret;

That i-- took me a minute to grok, but there isn't something immensely
better here.  If you have to resubmit these somehow, please add a
comment there.  But, otherwise, 

Acked-by: Dave Hansen <dave@sr71.net>

-- Dave