lantiq: fix maximum ethernet header length

The total ethernet frame length should be written to the hardware
register LTQ_ETOP_IGPLEN instead of just the value of the MTU. This
patch fixes network issues on various Danube boards, especially when
VLAN tagging is enabled.

Signed-off-by: Matti Laakso <malaakso at elisanet.fi>

SVN-Revision: 40541

target/linux/lantiq/patches-3.10/0207-NET-fix-etop-igplen.patch

@@ -0,0 +1,22 @@
+--- a/drivers/net/ethernet/lantiq_etop.c
++++ b/drivers/net/ethernet/lantiq_etop.c
+@@ -31,6 +31,7 @@
+ #include <linux/mm.h>
+ #include <linux/platform_device.h>
+ #include <linux/ethtool.h>
++#include <linux/if_vlan.h>
+ #include <linux/init.h>
+ #include <linux/delay.h>
+ #include <linux/io.h>
+@@ -764,8 +765,10 @@ ltq_etop_change_mtu(struct net_device *d
+ 		struct ltq_etop_priv *priv = netdev_priv(dev);
+ 		unsigned long flags;
+ 
++		int max = ETH_HLEN + VLAN_HLEN + new_mtu + ETH_FCS_LEN;
++
+ 		spin_lock_irqsave(&priv->lock, flags);
+-		ltq_etop_w32((ETOP_PLEN_UNDER << 16) | new_mtu,
++		ltq_etop_w32((ETOP_PLEN_UNDER << 16) | max,
+ 			LTQ_ETOP_IGPLEN);
+ 		spin_unlock_irqrestore(&priv->lock, flags);
+ 	}