[PATCH net 5/9] net: stmmac: xgmac: Only get SPH header len if available

[Jose Abreu <Jose.Abreu@synopsys.com>]

Split Header length is only available when L34T == 0. Fix this by
correctly checking if L34T is zero before trying to get Header length.

Fixes: 67afd6d1cfdf ("net: stmmac: Add Split Header support and enable it in XGMAC cores")
Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>

---
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Jose Abreu <joabreu@synopsys.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: netdev@vger.kernel.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c
index ae48154f933c..bd5838ce1e8a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_descs.c
@@ -288,7 +288,8 @@ static int dwxgmac2_get_rx_hash(struct dma_desc *p, u32 *hash,
 
 static int dwxgmac2_get_rx_header_len(struct dma_desc *p, unsigned int *len)
 {
-	*len = le32_to_cpu(p->des2) & XGMAC_RDES2_HL;
+	if (le32_to_cpu(p->des3) & XGMAC_RDES3_L34T)
+		*len = le32_to_cpu(p->des2) & XGMAC_RDES2_HL;
 	return 0;
 }
 
-- 
2.7.4