Re: [PATCH v2 net-next] sky2: use random address if EEPROM is bad

From: Stephen Hemminger
Date: Tue Aug 11 2015 - 13:01:27 EST


On Tue, 11 Aug 2015 15:35:56 +0100
Liviu Dudau <Liviu.Dudau@xxxxxxx> wrote:

> On some embedded systems the EEPROM does not contain a valid MAC address.
> In that case it is better to fallback to a generated mac address and
> let init scripts fix the value later.
>
> Reported-by: Liviu Dudau <Liviu.Dudau@xxxxxxx>
> Signed-off-by: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
> [Changed handcoded setup to use eth_hw_addr_random() instead]
> Signed-off-by: Liviu Dudau <Liviu.Dudau@xxxxxxx>
> ---
> I have tested this on my Juno platform and I can successfully do an nfsroot boot.
>
> Best regards,
> Liviu
>
> drivers/net/ethernet/marvell/sky2.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/net/ethernet/marvell/sky2.c b/drivers/net/ethernet/marvell/sky2.c
> index d9f4498..c309879 100644
> --- a/drivers/net/ethernet/marvell/sky2.c
> +++ b/drivers/net/ethernet/marvell/sky2.c
> @@ -4819,6 +4819,13 @@ static struct net_device *sky2_init_netdev(struct sky2_hw *hw, unsigned port,
> memcpy_fromio(dev->dev_addr, hw->regs + B2_MAC_1 + port * 8,
> ETH_ALEN);
>
> + /* if the address is invalid, use a random value */
> + if (!is_valid_ether_addr(dev->dev_addr)) {
> + netdev_warn(dev,
> + "Invalid MAC address, defaulting to random\n");
> + eth_hw_addr_random(dev);
> + }
> +
> return dev;
> }
>

This is not enough, you need to program the hardware with the new random MAC
address. The easiest way is calling sky2_set_mac_address, but you need to convert
the address from array back to sockaddr.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/