[net-next PATCH v3 1/5] net: dsa: tag_qca: return early if dev is not found

[Christian Marangi]

Currently checksum is recalculated and dsa tag stripped even if we later
don't find the dev.

To improve code, exit early if we don't find the dev and skip additional
operation on the skb since it will be freed anyway.

Signed-off-by: Christian Marangi <ansuelsmth@xxxxxxxxx>
Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
Reviewed-by: Vladimir Oltean <olteanv@xxxxxxxxx>
Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
---
changes v2:
- Add review tag

 net/dsa/tag_qca.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/dsa/tag_qca.c b/net/dsa/tag_qca.c
index e757c8de06f1..e5ff7c34e577 100644
--- a/net/dsa/tag_qca.c
+++ b/net/dsa/tag_qca.c
@@ -75,10 +75,6 @@ static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev)
 		return NULL;
 	}
 
-	/* Remove QCA tag and recalculate checksum */
-	skb_pull_rcsum(skb, QCA_HDR_LEN);
-	dsa_strip_etype_header(skb, QCA_HDR_LEN);
-
 	/* Get source port information */
 	port = FIELD_GET(QCA_HDR_RECV_SOURCE_PORT, hdr);
 
@@ -86,6 +82,10 @@ static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev)
 	if (!skb->dev)
 		return NULL;
 
+	/* Remove QCA tag and recalculate checksum */
+	skb_pull_rcsum(skb, QCA_HDR_LEN);
+	dsa_strip_etype_header(skb, QCA_HDR_LEN);
+
 	return skb;
 }
 
-- 
2.40.1