net: dsa: lantiq_gswip: fix maximum frame length

Currently, outgoing packets larger than 1496 bytes are dropped when
tagged VLAN is used on a switch port.

Add the frame check sequence length to the value of the register
GSWIP_MAC_FLEN to fix this. This matches the lantiq_ppa vendor driver,
which uses a value consisting of 1518 bytes for the MAC frame, plus the
lengths of special tag and VLAN tags.

Fixes: 14fceff4771e ("net: dsa: Add Lantiq / Intel DSA driver for vrx200")
Cc: stable@vger.kernel.org
Signed-off-by: Jan Hoffmann <jan@3e8.eu>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/lantiq_gswip.c b/drivers/net/dsa/lantiq_gswip.c
index e78026e..64d6dfa 100644 (file)
--- a/drivers/net/dsa/lantiq_gswip.c
+++ b/drivers/net/dsa/lantiq_gswip.c
@@ -843,7 +843,8 @@ static int gswip_setup(struct dsa_switch *ds)
 
        gswip_switch_mask(priv, 0, GSWIP_MAC_CTRL_2_MLEN,
                          GSWIP_MAC_CTRL_2p(cpu_port));
-       gswip_switch_w(priv, VLAN_ETH_FRAME_LEN + 8, GSWIP_MAC_FLEN);
+       gswip_switch_w(priv, VLAN_ETH_FRAME_LEN + 8 + ETH_FCS_LEN,
+                      GSWIP_MAC_FLEN);
        gswip_switch_mask(priv, 0, GSWIP_BM_QUEUE_GCTRL_GL_MOD,
                          GSWIP_BM_QUEUE_GCTRL);