[PATCH net v2] tg3: use random MAC address when tg3_get_device_address fails

[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 as fallback on our systems.

Make the driver assign a random address in this condition instead of
being fatal for probe.

v2: assign random address when tg3_get_device_address fails instead of
    changing its logic.

Fixes: e4c00ba7274b ("tg3: replace placeholder MAC address with device property")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/netdev/20260903233255.GA4109366@visor/t/#u
Signed-off-by: Ivan Delalande <colona@arista.com>
---
 drivers/net/ethernet/broadcom/tg3.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 73a4b569b03e..75cb0b0fab2f 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -17914,12 +17914,13 @@ static int tg3_init_one(struct pci_dev *pdev,
 	}
 
 	err = tg3_get_device_address(tp, addr);
-	if (err) {
-		dev_err(&pdev->dev,
-			"Could not obtain valid ethernet address, aborting\n");
-		goto err_out_apeunmap;
+	if (!err) {
+		eth_hw_addr_set(dev, addr);
+	} else {
+		dev_warn(&pdev->dev,
+			 "Could not obtain valid ethernet address, using a random address\n");
+		eth_hw_addr_random(dev);
 	}
-	eth_hw_addr_set(dev, addr);
 
 	intmbx = MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW;
 	rcvmbx = MAILBOX_RCVRET_CON_IDX_0 + TG3_64BIT_REG_LOW;
-- 
2.43.0