stmmac: do not call fix_mac_speed if NULL

On some platforms, fix_mac_speed is used for
configuring some sysconf registers according
to the working speed.
This patch fixes the fix_mac_speed invocation
that cannot be done if it is a NULL pointer.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/net/stmmac/stmmac_main.c b/drivers/net/stmmac/stmmac_main.c
index a02006d57a59..82ebbc0c8839 100644
--- a/drivers/net/stmmac/stmmac_main.c
+++ b/drivers/net/stmmac/stmmac_main.c
@@ -258,8 +258,9 @@ static void stmmac_adjust_link(struct net_device *dev)
                                 } else {
                                         ctrl &= ~priv->mac_type->hw.link.port;
                                 }
-                                priv->fix_mac_speed(priv->bsp_priv,
-                                                    phydev->speed);
+                                if (likely(priv->fix_mac_speed))
+                                        priv->fix_mac_speed(priv->bsp_priv,
+                                                            phydev->speed);
                                 break;
                         default:
                                 if (netif_msg_link(priv))