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

[Ivan Delalande <colona@arista.com>]

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 <colona@arista.com>
---
 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