net: mvneta: Fix big endian issue in mvneta_txq_desc_csum()

This commit fixes the command value generated for CSUM calculation when running in big endian mode. The Ethernet protocol ID for IP was being unconditionally byte-swapped in the layer 3 protocol check (with swab16), which caused the mvneta driver to not function correctly in big endian mode. This patch byte-swaps the ID conditionally with htons.

---
The mvneta driver existed prior to v3.13, but it has only supported big endian from v3.13 onward. If it's accepted, this patch needs to be backported for stable only as far back as v3.13.

 drivers/net/ethernet/marvell/mvneta.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

index 45beca1..667cf65 100644
@@ -1207,7 +1207,7 @@ static u32 mvneta_txq_desc_csum(int l3_offs, int l3_proto,
 	command =  l3_offs    << MVNETA_TX_L3_OFF_SHIFT;
 	command |= ip_hdr_len << MVNETA_TX_IP_HLEN_SHIFT;
 
-	if (l3_proto == swab16(ETH_P_IP))
+	if (l3_proto == htons(ETH_P_IP))
 		command |= MVNETA_TXD_IP_CSUM;
 	else
 		command |= MVNETA_TX_L3_IP6;

1.7.1

From: Thomas Fitzsimmons <[email protected]>
Date: Tue, 08 Jul 2014 19:44:07 -0400

Applied and queued up for -stable, thanks.