usbnet: add method for reporting speed without MII

The old method for reporting link speed assumed a driver uses the
generic phy (mii) MDIO read/write functions. CDC devices don't
expose the phy.

Add a primitive internal version reporting back directly what
the CDC notification/status operations recorded.

v2: rebased on upstream
v3: changed names and made clear which units are used
v4: moved hunks to correct patch; rewrote commmit messages

Signed-off-by: Oliver Neukum <[e-mail]>
Tested-by: Roland Dreier <[e-mail]>
Reviewed-by: Grant Grundler <[e-mail]>
Tested-by: Grant Grundler <[e-mail]>
Reviewed-by: Andrew Lunn <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/usb/usbnet.c

···
 }
 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_mii);
 
+int usbnet_get_link_ksettings_internal(struct net_device *net,
+					struct ethtool_link_ksettings *cmd)
+{
+	struct usbnet *dev = netdev_priv(net);
+
+	/* the assumption that speed is equal on tx and rx
+	 * is deeply engrained into the networking layer.
+	 * For wireless stuff it is not true.
+	 * We assume that rx_speed matters more.
+	 */
+	if (dev->rx_speed != SPEED_UNSET)
+		cmd->base.speed = dev->rx_speed / 1000000;
+	else if (dev->tx_speed != SPEED_UNSET)
+		cmd->base.speed = dev->tx_speed / 1000000;
+	else
+		cmd->base.speed = SPEED_UNKNOWN;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_internal);
+
 int usbnet_set_link_ksettings_mii(struct net_device *net,
 			      const struct ethtool_link_ksettings *cmd)
 {
···
 	dev->intf = udev;
 	dev->driver_info = info;
 	dev->driver_name = name;
+	dev->rx_speed = SPEED_UNSET;
+	dev->tx_speed = SPEED_UNSET;
 
 	net->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 	if (!net->tstats)

include/linux/usb/usbnet.h

···
 	u32			hard_mtu;	/* count any extra framing */
 	size_t			rx_urb_size;	/* size for rx urbs */
 	struct mii_if_info	mii;
+	long			rx_speed;	/* If MII not used */
+	long			tx_speed;	/* If MII not used */
+#		define SPEED_UNSET	-1
 
 	/* various kinds of pending driver work */
 	struct sk_buff_head	rxq;
···
 #		define EVENT_LINK_CHANGE	11
 #		define EVENT_SET_RX_MODE	12
 #		define EVENT_NO_IP_ALIGN	13
-	u32			rx_speed;	/* in bps - NOT Mbps */
-	u32			tx_speed;	/* in bps - NOT Mbps */
 };
 
 static inline struct usb_driver *driver_of(struct usb_interface *intf)
···
 				     struct ethtool_link_ksettings *cmd);
 extern int usbnet_set_link_ksettings_mii(struct net_device *net,
 				     const struct ethtool_link_ksettings *cmd);
+extern int usbnet_get_link_ksettings_internal(struct net_device *net,
+				     struct ethtool_link_ksettings *cmd);
 extern u32 usbnet_get_link(struct net_device *net);
 extern u32 usbnet_get_msglevel(struct net_device *);
 extern void usbnet_set_msglevel(struct net_device *, u32);