usbnet: introduce usbnet_link_change API

This patch introduces the API of usbnet_link_change, so that
usbnet can handle link change centrally, which may help to
implement killing traffic URBs for saving USB bus bandwidth
and host controller power.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 14 insertions, 0 deletions

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 51f3192f3931..40e4237b0a3a 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1653,6 +1653,19 @@ int usbnet_manage_power(struct usbnet *dev, int on)
 }
 EXPORT_SYMBOL(usbnet_manage_power);
 
+void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
+{
+        /* update link after link is reseted */
+        if (link && !need_reset)
+                netif_carrier_on(dev->net);
+        else
+                netif_carrier_off(dev->net);
+
+        if (need_reset && link)
+                usbnet_defer_kevent(dev, EVENT_LINK_RESET);
+}
+EXPORT_SYMBOL(usbnet_link_change);
+
 /*-------------------------------------------------------------------------*/
 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
                              u16 value, u16 index, void *data, u16 size)
diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h
index 0e5ac93bab10..eb021b8f53bd 100644
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -245,5 +245,6 @@ extern void usbnet_get_drvinfo(struct net_device *, struct ethtool_drvinfo *);
 extern int usbnet_nway_reset(struct net_device *net);
 
 extern int usbnet_manage_power(struct usbnet *, int);
+extern void usbnet_link_change(struct usbnet *, bool, bool);
 
 #endif /* __LINUX_USB_USBNET_H */