Subject: Re: [PATCH] r8169: Load MAC address from device tree if present

From: Andrew Lunn <[email-masked]>
Date: Fri, 25 Jan 2019 15:57:11 +0100

On Fri, Jan 25, 2019 at 11:18:14AM +0100, Thierry Reding wrote:
> From: Thierry Reding <[email-masked]>
> 
> If the system was booted using a device tree and if the device tree
> contains a MAC address, use it instead of reading one from the EEPROM.
> This is useful in situations where the EEPROM isn't properly programmed
> or where the firmware wants to override the existing MAC address.
> 
> Signed-off-by: Thierry Reding <[email-masked]>
> ---
> Based on net-next.
> 
>  drivers/net/ethernet/realtek/r8169.c | 35 +++++++++++++++++-----------
>  1 file changed, 22 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
> index f574b6b557f9..fd9edd643ca5 100644
> --- a/drivers/net/ethernet/realtek/r8169.c
> +++ b/drivers/net/ethernet/realtek/r8169.c
> @@ -6957,6 +6957,21 @@ static int rtl_alloc_irq(struct rtl8169_private *tp)
>  	return pci_alloc_irq_vectors(tp->pci_dev, 1, 1, flags);
>  }
>  
> +static void rtl_read_mac_address(struct rtl8169_private *tp,
> +				 u8 mac_addr[ETH_ALEN])
> +{
> +	/* Get MAC address */
> +	switch (tp->mac_version) {
> +	case RTL_GIGA_MAC_VER_35 ... RTL_GIGA_MAC_VER_38:
> +	case RTL_GIGA_MAC_VER_40 ... RTL_GIGA_MAC_VER_51:
> +		*(u32 *)&mac_addr[0] = rtl_eri_read(tp, 0xe0, ERIAR_EXGMAC);
> +		*(u16 *)&mac_addr[4] = rtl_eri_read(tp, 0xe4, ERIAR_EXGMAC);
> +		break;
> +	default:
> +		break;
> +	}
> +}
> +
>  DECLARE_RTL_COND(rtl_link_list_ready_cond)
>  {
>  	return RTL_R8(tp, MCU) & LINK_LIST_RDY;
> @@ -7148,6 +7163,7 @@ static int rtl_get_ether_clk(struct rtl8169_private *tp)
>  static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>  {
>  	const struct rtl_cfg_info *cfg = rtl_cfg_infos + ent->driver_data;
> +	u8 mac_addr[ETH_ALEN] __aligned(4);

Hi Thierry

Maybe now would be a good time to cleanup this __aligned(4), pointer
aliasing, etc?

> +	/* get MAC address */
> +	if (eth_platform_get_mac_address(&pdev->dev, mac_addr))
> +		rtl_read_mac_address(tp, mac_addr);
> +

Maybe that could be made more readable with:

      err = eth_platform_get_mac_address(&pdev->dev, mac_addr);
      if (err)
      	 	rtl_read_mac_address(tp, mac_addr);

Thanks
	Andrew