net: dsa: bcm_sf2: Do not assume DSA master supports WoL

We assume in the bcm_sf2 driver that the DSA master network device
supports ethtool_ops::{get,set}_wol operations, which is not a given.
Avoid de-referencing potentially non-existent function pointers and
check them as we should.

Fixes: 96e65d7f3f88 ("net: dsa: bcm_sf2: add support for Wake-on-LAN")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/bcm_sf2.c b/drivers/net/dsa/bcm_sf2.c
index 17ec32b..14138d4 100644 (file)
--- a/drivers/net/dsa/bcm_sf2.c
+++ b/drivers/net/dsa/bcm_sf2.c
@@ -726,10 +726,11 @@ static void bcm_sf2_sw_get_wol(struct dsa_switch *ds, int port,
 {
        struct net_device *p = ds->ports[port].cpu_dp->master;
        struct bcm_sf2_priv *priv = bcm_sf2_to_priv(ds);
-       struct ethtool_wolinfo pwol;
+       struct ethtool_wolinfo pwol = { };
 
        /* Get the parent device WoL settings */
-       p->ethtool_ops->get_wol(p, &pwol);
+       if (p->ethtool_ops->get_wol)
+               p->ethtool_ops->get_wol(p, &pwol);
 
        /* Advertise the parent device supported settings */
        wol->supported = pwol.supported;
@@ -750,9 +751,10 @@ static int bcm_sf2_sw_set_wol(struct dsa_switch *ds, int port,
        struct net_device *p = ds->ports[port].cpu_dp->master;
        struct bcm_sf2_priv *priv = bcm_sf2_to_priv(ds);
        s8 cpu_port = ds->ports[port].cpu_dp->index;
-       struct ethtool_wolinfo pwol;
+       struct ethtool_wolinfo pwol =  { };
 
-       p->ethtool_ops->get_wol(p, &pwol);
+       if (p->ethtool_ops->get_wol)
+               p->ethtool_ops->get_wol(p, &pwol);
        if (wol->wolopts & ~pwol.supported)
                return -EINVAL;