[PATCH 2/2] MPC52xx FEC: be more conservative when setting MII_SPEED register

[Wolfgang Denk]

This patch adds error checking and prevents clobbering unrelated bits
(reserved bits or the DIS_PREAMBLE bit) when writing the MII_SPEED
register on MPC52xx systems.

Signed-off-by: Wolfgang Denk <wd at denx.de>
Cc: Grant Likely <grant.likely at secretlab.ca>
Cc: Kumar Gala <galak at kernel.crashing.org>
Cc: <netdev at vger.kernel.org>
---
 drivers/net/fec_mpc52xx.c     |    2 +-
 drivers/net/fec_mpc52xx_phy.c |    6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/fec_mpc52xx.c b/drivers/net/fec_mpc52xx.c
index cc78633..b69d440 100644
--- a/drivers/net/fec_mpc52xx.c
+++ b/drivers/net/fec_mpc52xx.c
@@ -639,7 +639,7 @@ static void mpc52xx_fec_hw_init(struct net_device *dev)
 	/* set phy speed.
 	 * this can't be done in phy driver, since it needs to be called
 	 * before fec stuff (even on resume) */
-	out_be32(&fec->mii_speed, priv->mdio_speed);
+	clrsetbits_be32(&fec->mii_speed, 0x7E, priv->mdio_speed);
 }
 
 /**
diff --git a/drivers/net/fec_mpc52xx_phy.c b/drivers/net/fec_mpc52xx_phy.c
index 31e6d62..f733d43 100644
--- a/drivers/net/fec_mpc52xx_phy.c
+++ b/drivers/net/fec_mpc52xx_phy.c
@@ -105,8 +105,10 @@ static int mpc52xx_fec_mdio_probe(struct of_device *of,
 	dev_set_drvdata(dev, bus);
 
 	/* set MII speed */
-	out_be32(&priv->regs->mii_speed,
-		((mpc5xxx_get_bus_frequency(of->node) >> 20) / 5) << 1);
+	i = mpc5xxx_get_mii_speed(of);
+	if (i<0)
+		goto out_unmap;
+	clrsetbits_be32(&priv->regs->mii_speed, 0x7E, i);
 
 	err = of_mdiobus_register(bus, np);
 	if (err)
-- 
1.6.0.6