usbnet: Set link down initially for drivers that update link state

Some usbnet drivers update link state while others do not due to
hardware limitations.  Add a flag to distinguish those that do, and
set the link down initially for their devices.

This is intended to fix this bug: http://bugs.debian.org/444043

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/asix.c b/drivers/net/usb/asix.c
index 6ce7f77..1bef39a 100644
--- a/drivers/net/usb/asix.c
+++ b/drivers/net/usb/asix.c
@@ -1327,7 +1327,7 @@
 	.status = asix_status,
 	.link_reset = ax88172_link_reset,
 	.reset = ax88172_link_reset,
-	.flags =  FLAG_ETHER,
+	.flags =  FLAG_ETHER | FLAG_LINK_INTR,
 	.data = 0x00130103,
 };
 
@@ -1337,7 +1337,7 @@
 	.status = asix_status,
 	.link_reset = ax88172_link_reset,
 	.reset = ax88172_link_reset,
-	.flags =  FLAG_ETHER,
+	.flags =  FLAG_ETHER | FLAG_LINK_INTR,
 	.data = 0x009f9d9f,
 };
 
@@ -1347,7 +1347,7 @@
 	.status = asix_status,
 	.link_reset = ax88172_link_reset,
 	.reset = ax88172_link_reset,
-	.flags =  FLAG_ETHER,
+	.flags =  FLAG_ETHER | FLAG_LINK_INTR,
 	.data = 0x00130103,
 };
 
@@ -1357,7 +1357,7 @@
 	.status = asix_status,
 	.link_reset = ax88172_link_reset,
 	.reset = ax88172_link_reset,
-	.flags =  FLAG_ETHER,
+	.flags =  FLAG_ETHER | FLAG_LINK_INTR,
 	.data = 0x001f1d1f,
 };
 
@@ -1367,7 +1367,7 @@
 	.status = asix_status,
 	.link_reset = ax88772_link_reset,
 	.reset = ax88772_link_reset,
-	.flags = FLAG_ETHER | FLAG_FRAMING_AX,
+	.flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_LINK_INTR,
 	.rx_fixup = asix_rx_fixup,
 	.tx_fixup = asix_tx_fixup,
 };
@@ -1378,7 +1378,7 @@
 	.status = asix_status,
 	.link_reset = ax88178_link_reset,
 	.reset = ax88178_link_reset,
-	.flags = FLAG_ETHER | FLAG_FRAMING_AX,
+	.flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_LINK_INTR,
 	.rx_fixup = asix_rx_fixup,
 	.tx_fixup = asix_tx_fixup,
 };
diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index 71d7ff3..7ec24c9 100644
--- a/drivers/net/usb/cdc_ether.c
+++ b/drivers/net/usb/cdc_ether.c
@@ -413,7 +413,7 @@
 
 static const struct driver_info	cdc_info = {
 	.description =	"CDC Ethernet Device",
-	.flags =	FLAG_ETHER,
+	.flags =	FLAG_ETHER | FLAG_LINK_INTR,
 	// .check_connect = cdc_check_connect,
 	.bind =		cdc_bind,
 	.unbind =	usbnet_cdc_unbind,
diff --git a/drivers/net/usb/dm9601.c b/drivers/net/usb/dm9601.c
index a2b30a1..3d406f9 100644
--- a/drivers/net/usb/dm9601.c
+++ b/drivers/net/usb/dm9601.c
@@ -611,7 +611,7 @@
 
 static const struct driver_info dm9601_info = {
 	.description	= "Davicom DM9601 USB Ethernet",
-	.flags		= FLAG_ETHER,
+	.flags		= FLAG_ETHER | FLAG_LINK_INTR,
 	.bind		= dm9601_bind,
 	.rx_fixup	= dm9601_rx_fixup,
 	.tx_fixup	= dm9601_tx_fixup,
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 378da8c..04f3f28 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1352,9 +1352,11 @@
 	// ok, it's ready to go.
 	usb_set_intfdata (udev, dev);
 
-	// start as if the link is up
 	netif_device_attach (net);
 
+	if (dev->driver_info->flags & FLAG_LINK_INTR)
+		netif_carrier_off(net);
+
 	return 0;
 
 out3:
diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h
index 86c31b7..8c84881 100644
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -92,6 +92,7 @@
 #define FLAG_SEND_ZLP	0x0200		/* hw requires ZLPs are sent */
 #define FLAG_WWAN	0x0400		/* use "wwan%d" names */
 
+#define FLAG_LINK_INTR	0x0800		/* updates link (carrier) status */
 
 	/* init device ... can sleep, or cause probe() failure */
 	int	(*bind)(struct usbnet *, struct usb_interface *);