3 files changed, 31 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)
diff --git a/drivers/net/gianfar_mii.c b/drivers/net/gianfar_mii.c
index bf73eea98010..0e2595d24933 100644
--- a/drivers/net/gianfar_mii.c
+++ b/drivers/net/gianfar_mii.c
@@ -269,6 +269,27 @@ static struct device_driver gianfar_mdio_driver = {
         .remove = gfar_mdio_remove,
 };
 
+static int match_mdio_bus(struct device *dev, void *data)
+{
+        const struct gfar_private *priv = data;
+        const struct platform_device *pdev = to_platform_device(dev);
+
+        return !strcmp(pdev->name, gianfar_mdio_driver.name) &&
+                pdev->id == priv->einfo->mdio_bus;
+}
+
+/* Given a gfar_priv structure, find the mii_bus controlled by this device (not
+ * necessarily the same as the bus the gfar's PHY is on), if one exists.
+ * Normally only the first gianfar controls a mii_bus.  */
+struct mii_bus *gfar_get_miibus(const struct gfar_private *priv)
+{
+        /*const*/ struct device *d;
+
+        d = bus_find_device(gianfar_mdio_driver.bus, NULL, (void *)priv,
+                            match_mdio_bus);
+        return d ? dev_get_drvdata(d) : NULL;
+}
+
 int __init gfar_mdio_init(void)
 {
         return driver_register(&gianfar_mdio_driver);
diff --git a/drivers/net/gianfar_mii.h b/drivers/net/gianfar_mii.h
index 2af28b16a0e2..02dc970ca1ff 100644
--- a/drivers/net/gianfar_mii.h
+++ b/drivers/net/gianfar_mii.h
@@ -18,6 +18,8 @@
 #ifndef __GIANFAR_MII_H
 #define __GIANFAR_MII_H
 
+struct gfar_private; /* forward ref */
+
 #define MIIMIND_BUSY            0x00000001
 #define MIIMIND_NOTVALID        0x00000004
 
@@ -44,6 +46,7 @@ int gfar_mdio_write(struct mii_bus *bus, int mii_id, int regnum, u16 value);
 int gfar_local_mdio_write(struct gfar_mii __iomem *regs, int mii_id,
                           int regnum, u16 value);
 int gfar_local_mdio_read(struct gfar_mii __iomem *regs, int mii_id, int regnum);
+struct mii_bus *gfar_get_miibus(const struct gfar_private *priv);
 int __init gfar_mdio_init(void);
 void gfar_mdio_exit(void);
 #endif /* GIANFAR_PHY_H */