Re: [PATCH 001/001] leds: alix-leds2 fixed for Award BIOS

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 13 May 2009 16:10:27 +0200
Tobias M__ller <Tobias_Mueller@twam.info> wrote:

> From: Tobias Mueller <Tobias_Mueller@twam.info>
> 
> Added initialisation of GPIO ports for compatibility with boards with Award
> BIOS (e.g. ALIX.3D3).
> Signed-off-by: Tobias Mueller <Tobias_Mueller@twam.info>
> ---
> diff --git a/drivers/leds/leds-alix2.c b/drivers/leds/leds-alix2.c
> index ddbd773..bda9403 100644
> --- a/drivers/leds/leds-alix2.c
> +++ b/drivers/leds/leds-alix2.c
> @@ -14,7 +14,7 @@
> 
>  static int force = 0;
>  module_param(force, bool, 0444);
> -MODULE_PARM_DESC(force, "Assume system has ALIX.2 style LEDs");
> +MODULE_PARM_DESC(force, "Assume system has ALIX.2/ALIX.3 style LEDs");
> 
>  struct alix_led {
>  	struct led_classdev cdev;
> @@ -155,6 +155,11 @@ static int __init alix_led_init(void)
>  		goto out;
>  	}
> 
> +	/* enable output on GPIO for LED 1,2,3 */
> +	outl(1 << 6, 0x6104);
> +	outl(1 << 9, 0x6184);
> +	outl(1 << 11, 0x6184);
> +
>  	pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0);
>  	if (!IS_ERR(pdev)) {
>  		ret = platform_driver_probe(&alix_led_driver, alix_led_probe);

Will this cause problems on boards which are _not_ running that BIOS?

IOW, is this change backward-compatible?