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>

drivers/net/ethernet/micrel/ks8851.c

@@ -342,6 +342,26 @@ static void ks8851_soft_reset(struct ks8851_net *ks, unsigned op)
 	mdelay(1);	/* wait for condition to clear */
 }
 
+/**
+ * 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);
 
@@ -764,26 +791,6 @@ static void ks8851_tx_work(struct work_struct *work)
 	mutex_unlock(&ks->lock);
 }
 
-/**
- * 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.

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