net: dsa: handle non-existing PHYs on switch internal bus

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: b31f65fb43 ("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>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Florian Fainelli 2014-12-11 12:49:15 -08:00 committed by David S. Miller
parent 70e71ca0af
commit 53013c7743

View File

@ -555,6 +555,9 @@ 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 {