KSZ8851-SNL: Fix MAC address change problem

When device is off it is under power saving mode. Changing the MAC address
in that situation will result in the device not communicating as the first
write to the MAC address register is not executed.

Signed-off-by: Tristram Ha <Tristram.Ha@micrel.com>
[ben@simtec.co.uk: cleaned up header]
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 28 insertions, 21 deletions

diff --git a/drivers/net/ethernet/micrel/ks8851.c b/drivers/net/ethernet/micrel/ks8851.c
index d1669bcd4b4d..208e25a9e08c 100644
--- a/drivers/net/ethernet/micrel/ks8851.c
+++ b/drivers/net/ethernet/micrel/ks8851.c
@@ -343,6 +343,26 @@ static void ks8851_soft_reset(struct ks8851_net *ks, unsigned op)
 }
 
 /**
+ * ks8851_set_powermode - set power mode of the device
+ * @ks: The device state
+ * @pwrmode: The power mode value to write to KS_PMECR.
+ *
+ * Change the power mode of the chip.
+ */
+static void ks8851_set_powermode(struct ks8851_net *ks, unsigned pwrmode)
+{
+        unsigned pmecr;
+
+        netif_dbg(ks, hw, ks->netdev, "setting power mode %d\n", pwrmode);
+
+        pmecr = ks8851_rdreg16(ks, KS_PMECR);
+        pmecr &= ~PMECR_PM_MASK;
+        pmecr |= pwrmode;
+
+        ks8851_wrreg16(ks, KS_PMECR, pmecr);
+}
+
+/**
  * ks8851_write_mac_addr - write mac address to device registers
  * @dev: The network device
  *
@@ -358,8 +378,15 @@ static int ks8851_write_mac_addr(struct net_device *dev)
 
         mutex_lock(&ks->lock);
 
+        /*
+         * Wake up chip in case it was powered off when stopped; otherwise,
+         * the first write to the MAC address does not take effect.
+         */
+        ks8851_set_powermode(ks, PMECR_PM_NORMAL);
         for (i = 0; i < ETH_ALEN; i++)
                 ks8851_wrreg8(ks, KS_MAR(i), dev->dev_addr[i]);
+        if (!netif_running(dev))
+                ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
 
         mutex_unlock(&ks->lock);
 
@@ -765,26 +792,6 @@ static void ks8851_tx_work(struct work_struct *work)
 }
 
 /**
- * ks8851_set_powermode - set power mode of the device
- * @ks: The device state
- * @pwrmode: The power mode value to write to KS_PMECR.
- *
- * Change the power mode of the chip.
- */
-static void ks8851_set_powermode(struct ks8851_net *ks, unsigned pwrmode)
-{
-        unsigned pmecr;
-
-        netif_dbg(ks, hw, ks->netdev, "setting power mode %d\n", pwrmode);
-
-        pmecr = ks8851_rdreg16(ks, KS_PMECR);
-        pmecr &= ~PMECR_PM_MASK;
-        pmecr |= pwrmode;
-
-        ks8851_wrreg16(ks, KS_PMECR, pmecr);
-}
-
-/**
  * ks8851_net_open - open network device
  * @dev: The network device being opened.
  *
diff --git a/drivers/net/ethernet/micrel/ks8851.h b/drivers/net/ethernet/micrel/ks8851.h
index 537fb06e5932..b2703a11d04b 100644
--- a/drivers/net/ethernet/micrel/ks8851.h
+++ b/drivers/net/ethernet/micrel/ks8851.h
@@ -16,7 +16,7 @@
 #define CCR_32PIN                               (1 << 0)
 
 /* MAC address registers */
-#define KS_MAR(_m)                              0x15 - (_m)
+#define KS_MAR(_m)                              (0x15 - (_m))
 #define KS_MARL                                 0x10
 #define KS_MARM                                 0x12
 #define KS_MARH                                 0x14