ucc_geth: Don't needlessly change MAC settings in adjust_link()

If PHY doesn't have an IRQ, phylib would poll for link changes, and
would call adjust_link() every second. In that case we disable and
enable the controller every second.

Let's better check if there is actually anything changed, and, if so,
change the MAC settings.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 15 deletions

diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c
index 7fff4c5a1693..41ad2f3697c7 100644
--- a/drivers/net/ucc_geth.c
+++ b/drivers/net/ucc_geth.c
@@ -1651,25 +1651,28 @@ static void adjust_link(struct net_device *dev)
                         ugeth->oldspeed = phydev->speed;
                 }
 
-                /*
-                 * To change the MAC configuration we need to disable the
-                 * controller. To do so, we have to either grab ugeth->lock,
-                 * which is a bad idea since 'graceful stop' commands might
-                 * take quite a while, or we can quiesce driver's activity.
-                 */
-                ugeth_quiesce(ugeth);
-                ugeth_disable(ugeth, COMM_DIR_RX_AND_TX);
-
-                out_be32(&ug_regs->maccfg2, tempval);
-                out_be32(&uf_regs->upsmr, upsmr);
-
-                ugeth_enable(ugeth, COMM_DIR_RX_AND_TX);
-                ugeth_activate(ugeth);
-
                 if (!ugeth->oldlink) {
                         new_state = 1;
                         ugeth->oldlink = 1;
                 }
+
+                if (new_state) {
+                        /*
+                         * To change the MAC configuration we need to disable
+                         * the controller. To do so, we have to either grab
+                         * ugeth->lock, which is a bad idea since 'graceful
+                         * stop' commands might take quite a while, or we can
+                         * quiesce driver's activity.
+                         */
+                        ugeth_quiesce(ugeth);
+                        ugeth_disable(ugeth, COMM_DIR_RX_AND_TX);
+
+                        out_be32(&ug_regs->maccfg2, tempval);
+                        out_be32(&uf_regs->upsmr, upsmr);
+
+                        ugeth_enable(ugeth, COMM_DIR_RX_AND_TX);
+                        ugeth_activate(ugeth);
+                }
         } else if (ugeth->oldlink) {
                         new_state = 1;
                         ugeth->oldlink = 0;