net: dsa: microchip: fix tag_ksz egress mask for KSZ8795 family

Fix the tag_ksz egress mask for DSA_TAG_PROTO_KSZ8795, the port is
encoded in the two and not three LSB. This fix is for completeness,
for example the bug doesn't manifest itself on the KSZ8794 because bit
2 seems to be always zero.

Signed-off-by: Pieter Van Trappen <pieter.van.trappen@cern.ch>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Link: https://patch.msgid.link/20240813142750.772781-7-vtpieter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
index ee7b272ab71598b43183bd1d51856a65b23fa990..1f46de394f2e878765ed7d66daab9b0486f41c69 100644 (file)
--- a/net/dsa/tag_ksz.c
+++ b/net/dsa/tag_ksz.c
@@ -111,9 +111,10 @@ static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
  * ---------------------------------------------------------------------------
  * tag0 : zero-based value represents port
- *       (eg, 0x00=port1, 0x02=port3, 0x06=port7)
+ *       (eg, 0x0=port1, 0x2=port3, 0x3=port4)
  */
 
+#define KSZ8795_TAIL_TAG_EG_PORT_M     GENMASK(1, 0)
 #define KSZ8795_TAIL_TAG_OVERRIDE      BIT(6)
 #define KSZ8795_TAIL_TAG_LOOKUP                BIT(7)
 
@@ -141,7 +142,8 @@ static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev)
 {
        u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
 
-       return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN);
+       return ksz_common_rcv(skb, dev, tag[0] & KSZ8795_TAIL_TAG_EG_PORT_M,
+                             KSZ_EGRESS_TAG_LEN);
 }
 
 static const struct dsa_device_ops ksz8795_netdev_ops = {