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path: root/drivers/net/gianfar.c
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Diffstat (limited to 'drivers/net/gianfar.c')
-rw-r--r--drivers/net/gianfar.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index 15c422387028..013525f3c3bd 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -584,6 +584,18 @@ 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);
+
+ /* If the link is already up, we must already be ok, and don't need to
+ * configure and reset the TBI<->SerDes link. Maybe U-Boot configured
+ * everything for us? Resetting it takes the link down and requires
+ * several seconds for it to come back.
+ */
+ if (gfar_local_mdio_read(regs, tbipa, MII_BMSR) & BMSR_LSTATUS)
+ goto done;
/* Single clk mode, mii mode off(for serdes communication) */
gfar_local_mdio_write(regs, tbipa, MII_TBICON, TBICON_CLK_SELECT);
@@ -594,6 +606,10 @@ 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);
+
+ done:
+ if (bus)
+ mutex_unlock(&bus->mdio_lock);
}
static void init_registers(struct net_device *dev)