[PATCH] staging/panel: Prevent double-calling of parport_release - fix oops.

[Willy Tarreau]

On Wed, Jul 07, 2010 at 04:52:16AM +0200, Peter Huewe wrote:
> From: Peter Huewe <peterhuewe at gmx.de>
> 
> This patch prevents the code from calling parport_release and
> parport_unregister_device twice with the same arguments - and thus fixes an oops.
> 
> Rationale:
> After the first call the parport is already released and the
> handle isn't valid anymore and calling parport_release and
> parport_unregister_device twice isn't a good idea.
> 
> Signed-off-by: Peter Huewe <peterhuewe at gmx.de>
> ---
> KernelVersion: linux-next-20100607
> 
>  drivers/staging/panel/panel.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/staging/panel/panel.c b/drivers/staging/panel/panel.c
> index 3154ffe..6fa57be 100644
> --- a/drivers/staging/panel/panel.c
> +++ b/drivers/staging/panel/panel.c
> @@ -2277,6 +2277,7 @@ int panel_init(void)
>  		if (pprt) {
>  			parport_release(pprt);
>  			parport_unregister_device(pprt);
> +			pprt = NULL;
>  		}
>  		parport_unregister_driver(&panel_driver);
>  		printk(KERN_ERR "Panel driver version " PANEL_VERSION
> @@ -2327,6 +2328,7 @@ static void __exit panel_cleanup_module(void)
>  		/* TODO: free all input signals */
>  		parport_release(pprt);
>  		parport_unregister_device(pprt);
> +		pprt = NULL;
>  	}
>  	parport_unregister_driver(&panel_driver);
>  }
> -- 
> 1.7.1

look fine, ACK by me !

Willy