Subject: [PATCH] net: ethernet: mtk_eth_soc: fix rx vlan offload
From: Felix Fietkau <[email-masked]>
Date: Wed, 26 Aug 2020 16:52:12 +0200

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

Signed-off-by: Felix Fietkau <[email-masked]>
---

--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1320,7 +1320,7 @@ static int mtk_poll_rx(struct napi_struc
 		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);
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -295,6 +295,7 @@
 #define RX_DMA_LSO		BIT(30)
 #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)