Subject: Re: [PATCH net-next 07/19] net: usb: aqc111: Add support for getting and setting of MAC address

From: Andrew Lunn <[email-masked]>
Date: Sat, 6 Oct 2018 03:03:46 +0200

On Fri, Oct 05, 2018 at 10:24:58AM +0000, Igor Russkikh wrote:
> From: Dmitry Bezrukov <[email-masked]>
> 
> Signed-off-by: Dmitry Bezrukov <[email-masked]>
> Signed-off-by: Igor Russkikh <[email-masked]>
> ---
>  drivers/net/usb/aqc111.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/net/usb/aqc111.h |  1 +
>  2 files changed, 52 insertions(+)
> 
> diff --git a/drivers/net/usb/aqc111.c b/drivers/net/usb/aqc111.c
> index 1d366f4a1c51..075f51cd04ab 100644
> --- a/drivers/net/usb/aqc111.c
> +++ b/drivers/net/usb/aqc111.c
> @@ -11,6 +11,7 @@
>  #include <linux/netdevice.h>
>  #include <linux/mii.h>
>  #include <linux/usb.h>
> +#include <linux/if_vlan.h>
>  #include <linux/usb/cdc.h>
>  #include <linux/usb/usbnet.h>
>  
> @@ -266,11 +267,46 @@ static void aqc111_set_phy_speed(struct usbnet *dev, u8 autoneg, u16 speed)
>  		aqc111_set_phy_speed_fw_iface(dev, aqc111_data);
>  }
>  
> +static int aqc111_set_mac_addr(struct net_device *net, void *p)
> +{
> +	struct usbnet *dev = netdev_priv(net);
> +	struct sockaddr *addr = p;
> +
> +	if (netif_running(net))
> +		return -EBUSY;
> +	if (!is_valid_ether_addr(addr->sa_data))
> +		return -EADDRNOTAVAIL;

It is probably better to use eth_mac_addr().

> +
> +	memcpy(net->dev_addr, addr->sa_data, ETH_ALEN);
> +
> +	/* Set the MAC address */
> +	return aqc111_write_cmd(dev, AQ_ACCESS_MAC, SFR_NODE_ID, ETH_ALEN,
> +				ETH_ALEN, net->dev_addr);
> +}
> +
>  static const struct net_device_ops aqc111_netdev_ops = {
>  	.ndo_open		= usbnet_open,
>  	.ndo_stop		= usbnet_stop,
> +	.ndo_set_mac_address	= aqc111_set_mac_addr,
> +	.ndo_validate_addr	= eth_validate_addr,
>  };
>  
> +static int aqc111_get_mac(struct usbnet *dev, u8 *buf)
> +{
> +	int ret;
> +
> +	ret = aqc111_read_cmd(dev, AQ_FLASH_PARAMETERS, 0, 0, 6, buf);

ETH_ALEN instead of 6?

> +	if (ret < 0)
> +		goto out;
> +
> +	memcpy(dev->net->dev_addr, buf, ETH_ALEN);
> +	memcpy(dev->net->perm_addr, dev->net->dev_addr, ETH_ALEN);

Is this really the permanent address? If i call aqc111_set_mac_addr()
followed by aqc111_get_mac() i still get what is in the OTP EEPROM?

 +
> +	return 0;
> +out:
> +	return ret;
> +}
> +
>  static void aqc111_read_fw_version(struct usbnet *dev,
>  				   struct aqc111_data *aqc111_data)
>  {
> @@ -289,6 +325,7 @@ static void aqc111_read_fw_version(struct usbnet *dev,
>  
>  static int aqc111_bind(struct usbnet *dev, struct usb_interface *intf)
>  {
> +	u8 buf[6] = { 0 };

ETH_ALEN

>  	int ret;
>  	struct usb_device *udev = interface_to_usbdev(intf);
>  	struct aqc111_data *aqc111_data;
> @@ -316,6 +353,12 @@ static int aqc111_bind(struct usbnet *dev, struct usb_interface *intf)
>  	dev->data[0] = (unsigned long)aqc111_data;
>  	memset(aqc111_data, 0, sizeof(*aqc111_data));
>  
> +	/* Get the MAC address */
> +	memset(buf, 0, ETH_ALEN);

You initialized it above as {0}. You don't need to memset it here.

> +	ret = aqc111_get_mac(dev, buf);

Do you even need to zero it? If aqc111_get_mac() fails, it will be
left undefined, but you fail the bind anyway.

> +	if (ret)
> +		goto out;
> +
>  	dev->net->netdev_ops = &aqc111_netdev_ops;
>  
>  	aqc111_read_fw_version(dev, aqc111_data);
> @@ -324,6 +367,10 @@ static int aqc111_bind(struct usbnet *dev, struct usb_interface *intf)
>  					 SPEED_5000 : SPEED_1000;
>  
>  	return 0;
> +
> +out:
> +	kfree(aqc111_data);
> +	return ret;
>  }

   Andrew