[lm-sensors] [PATCH v2] hwmon: (smsc47m1) Fix compiler warning

[Robert Coulson]

Reviewed-by: Robert Coulson <robert.coulson at ericsson.com> 

> -----Original Message-----
> From: Guenter Roeck [mailto:linux at roeck-us.net] 
> Sent: Thursday, April 05, 2012 2:52 PM
> To: lm-sensors
> Cc: Robert Coulson; Guenter Roeck
> Subject: [PATCH v2] hwmon: (smsc47m1) Fix compiler warning
> 
> Some configurations produce the following compiler warning:
> 
> drivers/hwmon/smsc47m1.c: In function 'sm_smsc47m1_init':
> drivers/hwmon/smsc47m1.c:938: warning: 'address' may be used 
> uninitialized in this function
> 
> While this is a false positive, it can easily be fixed by 
> overloading the return
> value from smsc47m1_find with both address and error return 
> code (the address
> is an unsigned short and thus never negative). This also 
> reduces module size by
> a few bytes (46 bytes for x86_64).
> 
> Signed-off-by: Guenter Roeck <linux at roeck-us.net>
> ---
> v2: Don't assign an integer return value to an unsigned
> 
>  drivers/hwmon/smsc47m1.c |   19 ++++++++++---------
>  1 files changed, 10 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/hwmon/smsc47m1.c b/drivers/hwmon/smsc47m1.c
> index c590c14..b5aa38d 100644
> --- a/drivers/hwmon/smsc47m1.c
> +++ b/drivers/hwmon/smsc47m1.c
> @@ -491,10 +491,10 @@ static const struct attribute_group 
> smsc47m1_group = {
>  	.attrs = smsc47m1_attributes,
>  };
>  
> -static int __init smsc47m1_find(unsigned short *addr,
> -				struct smsc47m1_sio_data *sio_data)
> +static int __init smsc47m1_find(struct smsc47m1_sio_data *sio_data)
>  {
>  	u8 val;
> +	unsigned short addr;
>  
>  	superio_enter();
>  	val = force_id ? force_id : superio_inb(SUPERIO_REG_DEVID);
> @@ -546,9 +546,9 @@ static int __init smsc47m1_find(unsigned 
> short *addr,
>  	}
>  
>  	superio_select();
> -	*addr = (superio_inb(SUPERIO_REG_BASE) << 8)
> +	addr = (superio_inb(SUPERIO_REG_BASE) << 8)
>  	      |  superio_inb(SUPERIO_REG_BASE + 1);
> -	if (*addr == 0) {
> +	if (addr == 0) {
>  		pr_info("Device address not set, will not use\n");
>  		superio_exit();
>  		return -ENODEV;
> @@ -565,7 +565,7 @@ static int __init smsc47m1_find(unsigned 
> short *addr,
>  	}
>  
>  	superio_exit();
> -	return 0;
> +	return addr;
>  }
>  
>  /* Restore device to its initial state */
> @@ -938,13 +938,15 @@ static int __init sm_smsc47m1_init(void)
>  	unsigned short address;
>  	struct smsc47m1_sio_data sio_data;
>  
> -	if (smsc47m1_find(&address, &sio_data))
> -		return -ENODEV;
> +	err = smsc47m1_find(&sio_data);
> +	if (err < 0)
> +		return err;
> +	address = err;
>  
>  	/* Sets global pdev as a side effect */
>  	err = smsc47m1_device_add(address, &sio_data);
>  	if (err)
> -		goto exit;
> +		return err;
>  
>  	err = platform_driver_probe(&smsc47m1_driver, smsc47m1_probe);
>  	if (err)
> @@ -955,7 +957,6 @@ static int __init sm_smsc47m1_init(void)
>  exit_device:
>  	platform_device_unregister(pdev);
>  	smsc47m1_restore(&sio_data);
> -exit:
>  	return err;
>  }
>  
> -- 
> 1.7.5.4
> 
>