Re: [PATCH] net: dsa: mv88e6xxx: initialize return variable on declaration

[Andrew Lunn]

On Mon, Dec 06, 2021 at 04:32:19PM +0500, Ameer Hamza wrote:
> Uninitialized err variable defined in mv88e6393x_serdes_power
> function may cause undefined behaviour if it is called from
> mv88e6xxx_serdes_power_down context.
> 
> Addresses-Coverity: 1494644 ("Uninitialized scalar variable")
> 
> Signed-off-by: Ameer Hamza <amhamza.mgc@xxxxxxxxx>
> ---
>  drivers/net/dsa/mv88e6xxx/serdes.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
> index 55273013bfb5..33727439724a 100644
> --- a/drivers/net/dsa/mv88e6xxx/serdes.c
> +++ b/drivers/net/dsa/mv88e6xxx/serdes.c
> @@ -1507,7 +1507,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
>  			    bool on)
>  {
>  	u8 cmode = chip->ports[port].cmode;
> -	int err;
> +	int err = 0;
>  
>  	if (port != 0 && port != 9 && port != 10)
>  		return -EOPNOTSUPP;

Hi Marek

This warning likely comes from cmode not being a SERDES mode, and that
is not handles in the switch statementing. Do we want an

default:
	err = EINVAL;

?

	Andrew