Re: [PATCH] scsi/sym53c8xx: Fix a warning in sym_eh_handler

[Boaz Harrosh <bharrosh@panasas.com>]

On Wed, Oct 24 2007 at 11:59 +0200, Jean Delvare <khali@linux-fr.org> wrote:
> In 2.6.24-rc1 I see the following warning:
> drivers/scsi/sym53c8xx_2/sym_glue.c: In function "sym_eh_handler":
> drivers/scsi/sym53c8xx_2/sym_glue.c:612: warning: "io_reset" may be used uninitialized in this function
> 
> Although gcc is wrong and the code is actually correct, it can easily
> be made more obvious to keep the compiler quiet.
> 
> Signed-off-by: Jean Delvare <khali@linux-fr.org>
> ---
>  drivers/scsi/sym53c8xx_2/sym_glue.c |   13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
> 
> --- linux-2.6.24-rc1.orig/drivers/scsi/sym53c8xx_2/sym_glue.c	2007-10-24 09:59:46.000000000 +0200
> +++ linux-2.6.24-rc1/drivers/scsi/sym53c8xx_2/sym_glue.c	2007-10-24 11:53:14.000000000 +0200
> @@ -609,8 +609,8 @@ static int sym_eh_handler(int op, char *
>  	 */
>  #define WAIT_FOR_PCI_RECOVERY	35
>  	if (pci_channel_offline(pdev)) {
> -		struct completion *io_reset;
> -		int finished_reset = 0;
> +		struct completion *io_reset = NULL;
> +		int finished_reset;
>  		init_completion(&eh_done);
>  		spin_lock_irq(shost->host_lock);
>  		/* Make sure we didn't race */
> @@ -618,15 +618,14 @@ static int sym_eh_handler(int op, char *
>  			if (!sym_data->io_reset)
>  				sym_data->io_reset = &eh_done;
>  			io_reset = sym_data->io_reset;
> -		} else {
> -			finished_reset = 1;
>  		}
>  		spin_unlock_irq(shost->host_lock);
> -		if (!finished_reset)
> +		if (io_reset) {
>  			finished_reset = wait_for_completion_timeout(io_reset,
>  						WAIT_FOR_PCI_RECOVERY*HZ);
> -		if (!finished_reset)
> -			return SCSI_FAILED;
> +			if (!finished_reset)
> +				return SCSI_FAILED;
> +		}
>  	}
>  
>  	spin_lock_irq(shost->host_lock);
> 
> 
I think you should use uninitialized_var and not brute = NULL;
This is because, than uninitialized_var can be tested for in 
the future and removed if no longer relevant. And also for
the user of the code it is easier to understand.

Boaz