[PATCH net v2 4/8] net: stmmac: Only the last buffer has the FCS field

[Jose Abreu]

Only the last received buffer contains the FCS field. Check for end of
packet before trying to strip the FCS field.

Fixes: 88ebe2cf7f3f ("net: stmmac: Rework stmmac_rx()")
Signed-off-by: Jose Abreu <Jose.Abreu@xxxxxxxxxxxx>

---
Cc: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
Cc: Alexandre Torgue <alexandre.torgue@xxxxxx>
Cc: Jose Abreu <joabreu@xxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 2ebac89049ed..8c191e4d35d0 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3644,8 +3644,9 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
 		 * feature is always disabled and packets need to be
 		 * stripped manually.
 		 */
-		if (unlikely(priv->synopsys_id >= DWMAC_CORE_4_00) ||
-		    unlikely(status != llc_snap)) {
+		if (likely(!(status & rx_not_ls)) &&
+		    (likely(priv->synopsys_id >= DWMAC_CORE_4_00) ||
+		     unlikely(status != llc_snap))) {
 			if (buf2_len)
 				buf2_len -= ETH_FCS_LEN;
 			else
-- 
2.7.4