Re: [PATCH] net: mvneta: read MAC address from hardware when available

[Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>]

Hello.

On 06/03/2013 08:41 PM, Thomas Petazzoni wrote:

> This patch improves the logic used by the mvneta driver to find a MAC
> address for a particular interface. Until now, it was only looking at
> the Device Tree, and if no address was found, was falling back to
> generating a random MAC address.
>
> This patch adds the intermediate solution of reading the MAC address
> from the hardware registers, in case it has been set by the
> bootloader. So the order is now:
>
>   1) MAC address from the Device Tree
>   2) MAC address from the hardware registers
>   3) Random MAC address
>
> This requires moving the MAC address initialization a little bit later
> in the ->probe() code, because it now requires the hardware registers
> to be remapped.
>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> ---
>   drivers/net/ethernet/marvell/mvneta.c | 35 +++++++++++++++++++++++++++--------
>   1 file changed, 27 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
> index c966785..8c05cc5 100644
> --- a/drivers/net/ethernet/marvell/mvneta.c
> +++ b/drivers/net/ethernet/marvell/mvneta.c
> @@ -2251,6 +2251,20 @@ static int mvneta_change_mtu(struct net_device *dev, int mtu)
>   	return 0;
>   }
>   
> +/* Get mac address */
> +static void mvneta_get_mac_addr(struct mvneta_port *pp, unsigned char *addr)
> +{
> +	u32 mac_addr_l, mac_addr_h;

    Empty line wouldn't hurt here, after declaration.

> +	mac_addr_l = mvreg_read(pp, MVNETA_MAC_ADDR_LOW);
> +	mac_addr_h = mvreg_read(pp, MVNETA_MAC_ADDR_HIGH);
> +	addr[0] = (mac_addr_h >> 24) & 0xFF;
> +	addr[1] = (mac_addr_h >> 16) & 0xFF;
> +	addr[2] = (mac_addr_h >> 8) & 0xFF;
> +	addr[3] = mac_addr_h & 0xFF;
> +	addr[4] = (mac_addr_l >> 8) & 0xFF;
> +	addr[5] = mac_addr_l & 0xFF;
> +}
> +
>   /* Handle setting mac address */
>   static int mvneta_set_mac_addr(struct net_device *dev, void *addr)
>   {
>   
[...]
> @@ -2740,6 +2748,17 @@ static int mvneta_probe(struct platform_device *pdev)
>   
>   	clk_prepare_enable(pp->clk);
>   
> +	dt_mac_addr = of_get_mac_address(dn);
> +	if (dt_mac_addr && is_valid_ether_addr(dt_mac_addr))
> +		memcpy(dev->dev_addr, dt_mac_addr, ETH_ALEN);
> +	else {
> +		mvneta_get_mac_addr(pp, hw_mac_addr);
> +		if (is_valid_ether_addr(hw_mac_addr))
> +			memcpy(dev->dev_addr, hw_mac_addr, ETH_ALEN);
> +		else
> +			eth_hw_addr_random(dev);
> +	}

    {} should be on both arms of the *if* statement.

WBR, Sergei