[PATCH 5.16 112/227] net: dsa: lan9303: handle hwaccel VLAN tags

Greg Kroah-Hartman
2022-02-21T09:59:01Z

From: Mans Rullgard <mans@mansr.com>

commit 017b355bbdc6620fd8fe05fe297f553ce9d855ee upstream.

Check for a hwaccel VLAN tag on rx and use it if present. Otherwise,
use __skb_vlan_pop() like the other tag parsers do. This fixes the case
where the VLAN tag has already been consumed by the master.

Fixes: a1292595e006 ("net: dsa: add new DSA switch driver for the SMSC-LAN9303")
Signed-off-by: Mans Rullgard <mans@mansr.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20220216124634.23123-1-mans@mansr.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/dsa/tag_lan9303.c | 21 +++++++--------------
1 file changed, 7 insertions(+), 14 deletions(-)

--- a/net/dsa/tag_lan9303.c
+++ b/net/dsa/tag_lan9303.c
@@ -77,7 +77,6 @@ static struct sk_buff *lan9303_xmit(stru

static struct sk_buff *lan9303_rcv(struct sk_buff *skb, struct net_device *dev)
{
- __be16 *lan9303_tag;
u16 lan9303_tag1;
unsigned int source_port;

@@ -87,14 +86,15 @@ static struct sk_buff *lan9303_rcv(struc
return NULL;
}

- lan9303_tag = dsa_etype_header_pos_rx(skb);
-
- if (lan9303_tag[0] != htons(ETH_P_8021Q)) {
- dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid VLAN marker\n");
- return NULL;
+ if (skb_vlan_tag_present(skb)) {
+ lan9303_tag1 = skb_vlan_tag_get(skb);
+ __vlan_hwaccel_clear_tag(skb);
+ } else {
+ skb_push_rcsum(skb, ETH_HLEN);
+ __skb_vlan_pop(skb, &lan9303_tag1);
+ skb_pull_rcsum(skb, ETH_HLEN);
}

- lan9303_tag1 = ntohs(lan9303_tag[1]);
source_port = lan9303_tag1 & 0x3;

skb->dev = dsa_master_find_slave(dev, 0, source_port);
@@ -103,13 +103,6 @@ static struct sk_buff *lan9303_rcv(struc
return NULL;
}

- /* remove the special VLAN tag between the MAC addresses
- * and the current ethertype field.
- */
- skb_pull_rcsum(skb, 2 + 2);
-
- dsa_strip_etype_header(skb, LAN9303_TAG_LEN);
-
if (!(lan9303_tag1 & LAN9303_TAG_RX_TRAPPED_TO_CPU))
dsa_default_offload_fwd_mark(skb);