[PATCH 4.4 107/312] mlxsw: spectrum: Dont count internal TX header bytes to stats

[Greg Kroah-Hartman]

From: Nogah Frankel <nogahf@xxxxxxxxxxxx>

commit 63dcdd35c1552ca0c911e98ba3389a0729a457f4 upstream.

Stop the SW TX counter from counting the TX header bytes
since they are not being sent out.

Fixes: 56ade8fe3fe1 ("mlxsw: spectrum: Add initial support for Spectrum ASIC")
Reviewed-by: Ido Schimmel <idosch@xxxxxxxxxxxx>
Signed-off-by: Nogah Frankel <nogahf@xxxxxxxxxxxx>
Signed-off-by: Jiri Pirko <jiri@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/net/ethernet/mellanox/mlxsw/spectrum.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -399,7 +399,11 @@ static netdev_tx_t mlxsw_sp_port_xmit(st
 	}
 
 	mlxsw_sp_txhdr_construct(skb, &tx_info);
-	len = skb->len;
+	/* TX header is consumed by HW on the way so we shouldn't count its
+	 * bytes as being sent.
+	 */
+	len = skb->len - MLXSW_TXHDR_LEN;
+
 	/* Due to a race we might fail here because of a full queue. In that
 	 * unlikely case we simply drop the packet.
 	 */