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

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 3 Sep 2026 16:32:55 -0700 Ivan Delalande wrote:
> 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.

If there are so many cases with known-broken MAC addresses with tg3
shouldnt we do something like:

--- 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;

?