[PATCH AUTOSEL 4.19 31/32] net: ethernet: mtk_eth_soc: fix RX VLAN offload

[Sasha Levin]

From: Felix Fietkau <nbd@xxxxxxxx>

[ Upstream commit 3f57d8c40fea9b20543cab4da12f4680d2ef182c ]

The VLAN ID in the rx descriptor is only valid if the RX_DMA_VTAG bit is
set. Fixes frames wrongly marked with VLAN tags.

Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
[Ilya: fix commit message]
Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 2 +-
 drivers/net/ethernet/mediatek/mtk_eth_soc.h | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index b72a4fad7bc8..59f3dce3ab1d 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1041,7 +1041,7 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
 		skb->protocol = eth_type_trans(skb, netdev);
 
 		if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX &&
-		    RX_DMA_VID(trxd.rxd3))
+		    (trxd.rxd2 & RX_DMA_VTAG))
 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
 					       RX_DMA_VID(trxd.rxd3));
 		skb_record_rx_queue(skb, 0);
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 46819297fc3e..cb6b27861afa 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -285,6 +285,7 @@
 #define RX_DMA_DONE		BIT(31)
 #define RX_DMA_PLEN0(_x)	(((_x) & 0x3fff) << 16)
 #define RX_DMA_GET_PLEN0(_x)	(((_x) >> 16) & 0x3fff)
+#define RX_DMA_VTAG		BIT(15)
 
 /* QDMA descriptor rxd3 */
 #define RX_DMA_VID(_x)		((_x) & 0xfff)
-- 
2.30.2