macsonic: fix crash on PowerBook 520

No-one seems to know where the PowerBook 500 series store their ethernet
MAC addresses. So, rather than crash, use a MAC address from the SONIC
CAM. Failing that, generate a random one.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 60 insertions, 57 deletions

diff --git a/drivers/net/macsonic.c b/drivers/net/macsonic.c
index 61eabcac734c..b3d7d8d77f46 100644
--- a/drivers/net/macsonic.c
+++ b/drivers/net/macsonic.c
@@ -223,69 +223,73 @@ static int __devinit macsonic_init(struct net_device *dev)
         return 0;
 }
 
-static int __devinit mac_onboard_sonic_ethernet_addr(struct net_device *dev)
+#define INVALID_MAC(mac) (memcmp(mac, "\x08\x00\x07", 3) && \
+                          memcmp(mac, "\x00\xA0\x40", 3) && \
+                          memcmp(mac, "\x00\x80\x19", 3) && \
+                          memcmp(mac, "\x00\x05\x02", 3))
+
+static void __devinit mac_onboard_sonic_ethernet_addr(struct net_device *dev)
 {
         struct sonic_local *lp = netdev_priv(dev);
         const int prom_addr = ONBOARD_SONIC_PROM_BASE;
-        int i;
+        unsigned short val;
 
-        /* On NuBus boards we can sometimes look in the ROM resources.
-           No such luck for comm-slot/onboard. */
-        for(i = 0; i < 6; i++)
-                dev->dev_addr[i] = SONIC_READ_PROM(i);
+        /*
+         * On NuBus boards we can sometimes look in the ROM resources.
+         * No such luck for comm-slot/onboard.
+         * On the PowerBook 520, the PROM base address is a mystery.
+         */
+        if (hwreg_present((void *)prom_addr)) {
+                int i;
+
+                for (i = 0; i < 6; i++)
+                        dev->dev_addr[i] = SONIC_READ_PROM(i);
+                if (!INVALID_MAC(dev->dev_addr))
+                        return;
 
-        /* Most of the time, the address is bit-reversed.  The NetBSD
-           source has a rather long and detailed historical account of
-           why this is so. */
-        if (memcmp(dev->dev_addr, "\x08\x00\x07", 3) &&
-            memcmp(dev->dev_addr, "\x00\xA0\x40", 3) &&
-            memcmp(dev->dev_addr, "\x00\x80\x19", 3) &&
-            memcmp(dev->dev_addr, "\x00\x05\x02", 3))
+                /*
+                 * Most of the time, the address is bit-reversed. The NetBSD
+                 * source has a rather long and detailed historical account of
+                 * why this is so.
+                 */
                 bit_reverse_addr(dev->dev_addr);
-        else
-                return 0;
-
-        /* If we still have what seems to be a bogus address, we'll
-           look in the CAM.  The top entry should be ours. */
-        /* Danger! This only works if MacOS has already initialized
-           the card... */
-        if (memcmp(dev->dev_addr, "\x08\x00\x07", 3) &&
-            memcmp(dev->dev_addr, "\x00\xA0\x40", 3) &&
-            memcmp(dev->dev_addr, "\x00\x80\x19", 3) &&
-            memcmp(dev->dev_addr, "\x00\x05\x02", 3))
-        {
-                unsigned short val;
-
-                printk(KERN_INFO "macsonic: PROM seems to be wrong, trying CAM entry 15\n");
-
-                SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);
-                SONIC_WRITE(SONIC_CEP, 15);
-
-                val = SONIC_READ(SONIC_CAP2);
-                dev->dev_addr[5] = val >> 8;
-                dev->dev_addr[4] = val & 0xff;
-                val = SONIC_READ(SONIC_CAP1);
-                dev->dev_addr[3] = val >> 8;
-                dev->dev_addr[2] = val & 0xff;
-                val = SONIC_READ(SONIC_CAP0);
-                dev->dev_addr[1] = val >> 8;
-                dev->dev_addr[0] = val & 0xff;
-
-                printk(KERN_INFO "HW Address from CAM 15: %pM\n",
-                       dev->dev_addr);
-        } else return 0;
-
-        if (memcmp(dev->dev_addr, "\x08\x00\x07", 3) &&
-            memcmp(dev->dev_addr, "\x00\xA0\x40", 3) &&
-            memcmp(dev->dev_addr, "\x00\x80\x19", 3) &&
-            memcmp(dev->dev_addr, "\x00\x05\x02", 3))
-        {
+                if (!INVALID_MAC(dev->dev_addr))
+                        return;
+
                 /*
-                 * Still nonsense ... messed up someplace!
+                 * If we still have what seems to be a bogus address, we'll
+                 * look in the CAM. The top entry should be ours.
                  */
-                printk(KERN_ERR "macsonic: ERROR (INVALID MAC)\n");
-                return -EIO;
-        } else return 0;
+                printk(KERN_WARNING "macsonic: MAC address in PROM seems "
+                                    "to be invalid, trying CAM\n");
+        } else {
+                printk(KERN_WARNING "macsonic: cannot read MAC address from "
+                                    "PROM, trying CAM\n");
+        }
+
+        /* This only works if MacOS has already initialized the card. */
+
+        SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);
+        SONIC_WRITE(SONIC_CEP, 15);
+
+        val = SONIC_READ(SONIC_CAP2);
+        dev->dev_addr[5] = val >> 8;
+        dev->dev_addr[4] = val & 0xff;
+        val = SONIC_READ(SONIC_CAP1);
+        dev->dev_addr[3] = val >> 8;
+        dev->dev_addr[2] = val & 0xff;
+        val = SONIC_READ(SONIC_CAP0);
+        dev->dev_addr[1] = val >> 8;
+        dev->dev_addr[0] = val & 0xff;
+
+        if (!INVALID_MAC(dev->dev_addr))
+                return;
+
+        /* Still nonsense ... messed up someplace! */
+
+        printk(KERN_WARNING "macsonic: MAC address in CAM entry 15 "
+                            "seems invalid, will use a random MAC\n");
+        random_ether_addr(dev->dev_addr);
 }
 
 static int __devinit mac_onboard_sonic_probe(struct net_device *dev)
@@ -402,8 +406,7 @@ static int __devinit mac_onboard_sonic_probe(struct net_device *dev)
         SONIC_WRITE(SONIC_ISR, 0x7fff);
 
         /* Now look for the MAC address. */
-        if (mac_onboard_sonic_ethernet_addr(dev) != 0)
-                return -ENODEV;
+        mac_onboard_sonic_ethernet_addr(dev);
 
         /* Shared init code */
         return macsonic_init(dev);