[PATCH 4.8 23/35] net: fec: Call swap_buffer() prior to IP header alignment

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Fabio Estevam <fabio.estevam@xxxxxxx>


[ Upstream commit 235bde1ed3f0fff0f68f367ec8807b89ea151258 ]

Commit 3ac72b7b63d5 ("net: fec: align IP header in hardware") breaks
networking on mx28.

There is an erratum on mx28 (ENGR121613 - ENET big endian mode
not compatible with ARM little endian) that requires an additional
byte-swap operation to workaround this problem.

So call swap_buffer() prior to performing the IP header alignment
to restore network functionality on mx28.

Fixes: 3ac72b7b63d5 ("net: fec: align IP header in hardware")
Reported-and-tested-by: Henri Roosen <henri.roosen@xxxxxxxxxxxxx>
Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/freescale/fec_main.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1430,14 +1430,14 @@ fec_enet_rx_queue(struct net_device *nde
 		skb_put(skb, pkt_len - 4);
 		data = skb->data;
 
+		if (!is_copybreak && need_swap)
+			swap_buffer(data, pkt_len);
+
 #if !defined(CONFIG_M5272)
 		if (fep->quirks & FEC_QUIRK_HAS_RACC)
 			data = skb_pull_inline(skb, 2);
 #endif
 
-		if (!is_copybreak && need_swap)
-			swap_buffer(data, pkt_len);
-
 		/* Extract the enhanced buffer descriptor */
 		ebdp = NULL;
 		if (fep->bufdesc_ex)