[PATCH net v3 5/5] net: ethernet: mtk_eth_soc: ppe: fix L2 offloading with DSA untagging offload enabled

[Felix Fietkau]

Check for skb metadata in order to detect the case where the DSA header is not
present.

Fixes: 2d7605a72906 ("net: ethernet: mtk_eth_soc: enable hardware DSA untagging")
Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 6 +++---
 drivers/net/ethernet/mediatek/mtk_ppe.c     | 5 ++++-
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index ab6c571a39ae..cec2fcab3dfa 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -2039,9 +2039,6 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
 			skb_checksum_none_assert(skb);
 		skb->protocol = eth_type_trans(skb, netdev);
 
-		if (reason == MTK_PPE_CPU_REASON_HIT_UNBIND_RATE_REACHED)
-			mtk_ppe_check_skb(eth->ppe[0], skb, hash);
-
 		/* When using VLAN untagging in combination with DSA, the
 		 * hardware treats the MTK special tag as a VLAN and untags it.
 		 */
@@ -2054,6 +2051,9 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
 				skb_dst_set_noref(skb, &eth->dsa_meta[port]->dst);
 		}
 
+		if (reason == MTK_PPE_CPU_REASON_HIT_UNBIND_RATE_REACHED)
+			mtk_ppe_check_skb(eth->ppe[0], skb, hash);
+
 		skb_record_rx_queue(skb, 0);
 		napi_gro_receive(napi, skb);
 
diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c
index 269208a841c7..e366a83cf516 100644
--- a/drivers/net/ethernet/mediatek/mtk_ppe.c
+++ b/drivers/net/ethernet/mediatek/mtk_ppe.c
@@ -8,6 +8,7 @@
 #include <linux/platform_device.h>
 #include <linux/if_ether.h>
 #include <linux/if_vlan.h>
+#include <net/dst_metadata.h>
 #include <net/dsa.h>
 #include "mtk_eth_soc.h"
 #include "mtk_ppe.h"
@@ -700,7 +701,9 @@ void __mtk_ppe_check_skb(struct mtk_ppe *ppe, struct sk_buff *skb, u16 hash)
 		    skb->dev->dsa_ptr->tag_ops->proto != DSA_TAG_PROTO_MTK)
 			goto out;
 
-		tag += 4;
+		if (!skb_metadata_dst(skb))
+			tag += 4;
+
 		if (get_unaligned_be16(tag) != ETH_P_8021Q)
 			break;
 
-- 
2.38.1