Re: [PATCH v2 5/8] net: pxa168_eth: get and set the mac address on the Ethernet controller

From: Jason Cooper
Date: Tue Sep 09 2014 - 12:30:16 EST


On Tue, Sep 09, 2014 at 04:44:05PM +0200, Antoine Tenart wrote:
> When changing the MAC address, in addition to updating the dev_addr in
> the net_device structure, this patch also update the MAC address
> registers (high and low) of the Ethernet controller with the new MAC.
> The address stored in these registers is used for IEEE 802.3x Ethernet
> flow control, which is already enabled.
>
> This patch also tries reading the MAC address stored in these registers
> when probing the driver, to use the MAC address set by the bootloader
> and avoid using a random one.

Hmm, the wording here seems odd. I think the preference should be:

1) bootloader-supplied addr via DT
2) addr read from device
3) randomly generated one.

>
> Signed-off-by: Antoine Tenart <antoine.tenart@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/net/ethernet/marvell/pxa168_eth.c | 36 +++++++++++++++++++++++++++++--
> 1 file changed, 34 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/pxa168_eth.c b/drivers/net/ethernet/marvell/pxa168_eth.c
> index 10422f2df6cc..0ecbb3903b71 100644
> --- a/drivers/net/ethernet/marvell/pxa168_eth.c
> +++ b/drivers/net/ethernet/marvell/pxa168_eth.c
> @@ -60,6 +60,8 @@
> #define PORT_COMMAND 0x0410
> #define PORT_STATUS 0x0418
> #define HTPR 0x0428
> +#define MAC_ADDR_LOW 0x0430
> +#define MAC_ADDR_HIGH 0x0438
> #define SDMA_CONFIG 0x0440
> #define SDMA_CMD 0x0448
> #define INT_CAUSE 0x0450
> @@ -604,16 +606,42 @@ static void pxa168_eth_set_rx_mode(struct net_device *dev)
> update_hash_table_mac_address(pep, NULL, ha->addr);
> }
>
> +static void pxa168_eth_get_mac_address(struct net_device *dev,
> + unsigned char *addr)
> +{
> + struct pxa168_eth_private *pep = netdev_priv(dev);
> + unsigned int mac_h = rdl(pep, MAC_ADDR_HIGH);
> + unsigned int mac_l = rdl(pep, MAC_ADDR_LOW);
> +
> + addr[0] = (mac_h >> 24) & 0xff;
> + addr[1] = (mac_h >> 16) & 0xff;
> + addr[2] = (mac_h >> 8) & 0xff;
> + addr[3] = mac_h & 0xff;
> + addr[4] = (mac_l >> 8) & 0xff;
> + addr[5] = mac_l & 0xff;
> +}
> +
> static int pxa168_eth_set_mac_address(struct net_device *dev, void *addr)
> {
> struct sockaddr *sa = addr;
> struct pxa168_eth_private *pep = netdev_priv(dev);
> unsigned char oldMac[ETH_ALEN];
> + u32 mac_h, mac_l;
>
> if (!is_valid_ether_addr(sa->sa_data))
> return -EADDRNOTAVAIL;
> memcpy(oldMac, dev->dev_addr, ETH_ALEN);
> memcpy(dev->dev_addr, sa->sa_data, ETH_ALEN);
> +
> + mac_h = sa->sa_data[0] << 24;
> + mac_h |= sa->sa_data[1] << 16;
> + mac_h |= sa->sa_data[2] << 8;
> + mac_h |= sa->sa_data[3];
> + mac_l = sa->sa_data[4] << 8;
> + mac_l |= sa->sa_data[5];
> + wrl(pep, MAC_ADDR_HIGH, mac_h);
> + wrl(pep, MAC_ADDR_LOW, mac_l);
> +
> netif_addr_lock_bh(dev);
> update_hash_table_mac_address(pep, oldMac, dev->dev_addr);
> netif_addr_unlock_bh(dev);
> @@ -1494,8 +1522,12 @@ static int pxa168_eth_probe(struct platform_device *pdev)
>
> INIT_WORK(&pep->tx_timeout_task, pxa168_eth_tx_timeout_task);
>
> - dev_info(&pdev->dev, "Using random mac address\n");
> - eth_hw_addr_random(dev);
> + /* try reading the mac address, if set by the bootloader */
> + pxa168_eth_get_mac_address(dev, dev->dev_addr);
> + if (!is_valid_ether_addr(dev->dev_addr)) {
> + dev_info(&pdev->dev, "Using random mac address\n");
> + eth_hw_addr_random(dev);
> + }

I would do the above iff there was no valid addr supplied by the DT.

thx,

Jason.
>
> pep->rx_ring_size = NUM_RX_DESCS;
> pep->tx_ring_size = NUM_TX_DESCS;
> --
> 1.9.1
>
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