Re: [PATCH net 1/2] net: dsa: handle non-existing PHYs on switch internal bus

[Andrew Lunn <andrew@lunn.ch>]

On Thu, Dec 11, 2014 at 12:49:15PM -0800, Florian Fainelli wrote:
> In case there is no PHY at the designated address on the internal
> switch, we would basically de-reference a null pointer here:
> 
> dsa_slave_phy_setup(...)
> {
> 	p->phy = ds->slave_mii_bus->phy_map[p->port];
> 	phy_connect_direct(slave_dev, p->phy, dsa_slave_adjust_link,
> 				      ^------
> 
> This can be triggered when the platform configuration (platform_data or
> Device Tree) indicates there should be a PHY device at this address, but
> the HW is non-responsive, such that we cannot attach a PHY device at
> this specific location.
> 
> Fix this by checking the return value prior to calling
> phy_connect_direct().
> 
> CC: Andrew Lunn <andrew@lunn.ch>
> Fixes: b31f65fb4383 ("net: dsa: slave: Fix autoneg for phys on switch MDIO bus")
> Reported-by: Brian Norris <computersforpeace@gmail.com>
> Signed-off-by: Andrey Volkov <andrey.volkov@nexvision.fr>
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

Acked-by: Andrew Lunn <andrew@lunn.ch>

	  Andrew


> ---
>  net/dsa/slave.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/net/dsa/slave.c b/net/dsa/slave.c
> index ab03e00ffe8f..0efaab1e408b 100644
> --- a/net/dsa/slave.c
> +++ b/net/dsa/slave.c
> @@ -491,6 +491,9 @@ static void dsa_slave_phy_setup(struct dsa_slave_priv *p,
>  	 */
>  	if (!p->phy) {
>  		p->phy = ds->slave_mii_bus->phy_map[p->port];
> +		if (!p->phy)
> +			return;
> +
>  		phy_connect_direct(slave_dev, p->phy, dsa_slave_adjust_link,
>  				   p->phy_interface);
>  	} else {
> -- 
> 2.1.0
>