[TG3]: Fix probe failure due to invalid MAC address

Some older bootcode in some devices may report 0 MAC address in
SRAM when booting up from low power state. This patch fixes the
problem by checking for a valid MAC address in SRAM and falling back
to NVRAM if necessary.

Thanks to walt <wa1ter@myrealbox.com> for reporting the problem
and helping to debug it.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 28 insertions, 22 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index b5473325bff4..c41dbb0e8f14 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -10531,6 +10531,7 @@ static int __devinit tg3_get_device_address(struct tg3 *tp)
 {
         struct net_device *dev = tp->dev;
         u32 hi, lo, mac_offset;
+        int addr_ok = 0;
 
 #ifdef CONFIG_SPARC64
         if (!tg3_get_macaddr_sparc(tp))
@@ -10560,29 +10561,34 @@ static int __devinit tg3_get_device_address(struct tg3 *tp)
                 dev->dev_addr[3] = (lo >> 16) & 0xff;
                 dev->dev_addr[4] = (lo >>  8) & 0xff;
                 dev->dev_addr[5] = (lo >>  0) & 0xff;
-        }
-        /* Next, try NVRAM. */
-        else if (!(tp->tg3_flags & TG3_FLG2_SUN_570X) &&
-                 !tg3_nvram_read(tp, mac_offset + 0, &hi) &&
-                 !tg3_nvram_read(tp, mac_offset + 4, &lo)) {
-                dev->dev_addr[0] = ((hi >> 16) & 0xff);
-                dev->dev_addr[1] = ((hi >> 24) & 0xff);
-                dev->dev_addr[2] = ((lo >>  0) & 0xff);
-                dev->dev_addr[3] = ((lo >>  8) & 0xff);
-                dev->dev_addr[4] = ((lo >> 16) & 0xff);
-                dev->dev_addr[5] = ((lo >> 24) & 0xff);
-        }
-        /* Finally just fetch it out of the MAC control regs. */
-        else {
-                hi = tr32(MAC_ADDR_0_HIGH);
-                lo = tr32(MAC_ADDR_0_LOW);
 
-                dev->dev_addr[5] = lo & 0xff;
-                dev->dev_addr[4] = (lo >> 8) & 0xff;
-                dev->dev_addr[3] = (lo >> 16) & 0xff;
-                dev->dev_addr[2] = (lo >> 24) & 0xff;
-                dev->dev_addr[1] = hi & 0xff;
-                dev->dev_addr[0] = (hi >> 8) & 0xff;
+                /* Some old bootcode may report a 0 MAC address in SRAM */
+                addr_ok = is_valid_ether_addr(&dev->dev_addr[0]);
+        }
+        if (!addr_ok) {
+                /* Next, try NVRAM. */
+                if (!(tp->tg3_flags & TG3_FLG2_SUN_570X) &&
+                    !tg3_nvram_read(tp, mac_offset + 0, &hi) &&
+                    !tg3_nvram_read(tp, mac_offset + 4, &lo)) {
+                        dev->dev_addr[0] = ((hi >> 16) & 0xff);
+                        dev->dev_addr[1] = ((hi >> 24) & 0xff);
+                        dev->dev_addr[2] = ((lo >>  0) & 0xff);
+                        dev->dev_addr[3] = ((lo >>  8) & 0xff);
+                        dev->dev_addr[4] = ((lo >> 16) & 0xff);
+                        dev->dev_addr[5] = ((lo >> 24) & 0xff);
+                }
+                /* Finally just fetch it out of the MAC control regs. */
+                else {
+                        hi = tr32(MAC_ADDR_0_HIGH);
+                        lo = tr32(MAC_ADDR_0_LOW);
+
+                        dev->dev_addr[5] = lo & 0xff;
+                        dev->dev_addr[4] = (lo >> 8) & 0xff;
+                        dev->dev_addr[3] = (lo >> 16) & 0xff;
+                        dev->dev_addr[2] = (lo >> 24) & 0xff;
+                        dev->dev_addr[1] = hi & 0xff;
+                        dev->dev_addr[0] = (hi >> 8) & 0xff;
+                }
         }
 
         if (!is_valid_ether_addr(&dev->dev_addr[0])) {