cassini: Use local-mac-address prom property for Cassini MAC address

Fallback on the local-mac-address prom property if the Cassini device
does not have an address programmed in the VPD ROM. This uses the same
technique as implemented by the sungem driver.

The problem was reported by Frans van Berckel using Debian kernel 2.6.34-7
on Sun Fire V440. udev was assigning a new eth<n> device name on each reboot
because the cassini driver was using a random MAC address.

Fix tested on 2.6.34-7 and 2.6.37 Sun Fire V440. Compile tested against
2.6.36 davem/sparc-2.6.git
Reported-by: NFrans van Berckel <fberckel@xs4all.nl>
Tested-by: NFrans van Berckel <fberckel@xs4all.nl>
Reviewed-by: NJulian Calaby <julian.calaby@gmail.com>
Reviewed-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NRichard Mortimer <richm@oldelvet.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/cassini.c

@@ -3203,6 +3203,10 @@ static int cas_get_vpd_info(struct cas *cp, unsigned char *dev_addr,
 	int phy_type = CAS_PHY_MII_MDIO0; /* default phy type */
 	int mac_off  = 0;
 
+#if defined(CONFIG_OF)
+	const unsigned char *addr;
+#endif
+
 	/* give us access to the PROM */
 	writel(BIM_LOCAL_DEV_PROM | BIM_LOCAL_DEV_PAD,
 	       cp->regs + REG_BIM_LOCAL_DEV_EN);
@@ -3350,6 +3354,14 @@ static int cas_get_vpd_info(struct cas *cp, unsigned char *dev_addr,
 	if (found & VPD_FOUND_MAC)
 		goto done;
 
+#if defined(CONFIG_OF)
+	addr = of_get_property(cp->of_node, "local-mac-address", NULL);
+	if (addr != NULL) {
+		memcpy(dev_addr, addr, 6);
+		goto done;
+	}
+#endif
+
 	/* Sun MAC prefix then 3 random bytes. */
 	pr_info("MAC address not found in ROM VPD\n");
 	dev_addr[0] = 0x08;
@@ -5019,6 +5031,10 @@ static int __devinit cas_init_one(struct pci_dev *pdev,
 	cp->msg_enable = (cassini_debug < 0) ? CAS_DEF_MSG_ENABLE :
 	  cassini_debug;
 
+#if defined(CONFIG_OF)
+	cp->of_node = pci_device_to_OF_node(pdev);
+#endif
+
 	cp->link_transition = LINK_TRANSITION_UNKNOWN;
 	cp->link_transition_jiffies_valid = 0;
 

drivers/net/cassini.h

@@ -2868,6 +2868,9 @@ struct cas {
 	dma_addr_t block_dvma, tx_tiny_dvma[N_TX_RINGS];
 	struct pci_dev *pdev;
 	struct net_device *dev;
+#if defined(CONFIG_OF)
+	struct device_node	*of_node;
+#endif
 
 	/* Firmware Info */
 	u16			fw_load_addr;