[PATCH net] tg3: check NVRAM and control register if SRAM has the placeholder MAC address

Some of the tg3 NICs we use (BCM57762) reset the SRAM MAC address to the
placeholder address on link flaps, tg3_chip_reset, etc. We've typically
fixed it from userspace, but since e4c00ba7274b ("tg3: replace
placeholder MAC address with device property") was merged, tg3 just
fails probe as we don't have a way to get it through the generic
device_get_mac_address infrastructure on our systems.

Since that commit effectively made the placeholder address invalid,
include this check in the earlier `addr_ok` expression, so we proceed
with the NVRAM and control register fallback to find a valid MAC.

Fixes: e4c00ba7274b ("tg3: replace placeholder MAC address with device property")
Signed-off-by: Ivan Delalande <redacted>
---
 drivers/net/ethernet/broadcom/tg3.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 73a4b569b03e..0b47908f0935 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c

@@ -17081,7 +17081,8 @@ static int tg3_get_device_address(struct tg3 *tp, u8 *addr)
 		addr[5] = (lo >>  0) & 0xff;
 
 		/* Some old bootcode may report a 0 MAC address in SRAM */
-		addr_ok = is_valid_ether_addr(addr);
+		addr_ok = is_valid_ether_addr(addr) &&
+			  !tg3_is_default_mac_address(addr);
 	}
 	if (!addr_ok) {
 		__be32 be_hi, be_lo;

-- 
2.43.0