1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index 64b201134fdb..249541a1814b 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -586,6 +586,10 @@ static void gfar_configure_serdes(struct net_device *dev)
         struct gfar_mii __iomem *regs =
                         (void __iomem *)&priv->regs->gfar_mii_regs;
         int tbipa = gfar_read(&priv->regs->tbipa);
+        struct mii_bus *bus = gfar_get_miibus(priv);
+
+        if (bus)
+                mutex_lock(&bus->mdio_lock);
 
         /* Single clk mode, mii mode off(for serdes communication) */
         gfar_local_mdio_write(regs, tbipa, MII_TBICON, TBICON_CLK_SELECT);
@@ -596,6 +600,9 @@ static void gfar_configure_serdes(struct net_device *dev)
 
         gfar_local_mdio_write(regs, tbipa, MII_BMCR, BMCR_ANENABLE |
                         BMCR_ANRESTART | BMCR_FULLDPLX | BMCR_SPEED1000);
+
+        if (bus)
+                mutex_unlock(&bus->mdio_lock);
 }
 
 static void init_registers(struct net_device *dev)