[PATCH 5.15 312/317] net: dsa: mt7530: fix handling of 802.1X PAE frames

[Sasha Levin]

From: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>

[ Upstream commit e94b590abfff2cdbf0bdaa7d9904364c8d480af5 ]

802.1X PAE frames are link-local frames, therefore they must be trapped to
the CPU port. Currently, the MT753X switches treat 802.1X PAE frames as
regular multicast frames, therefore flooding them to user ports. To fix
this, set 802.1X PAE frames to be trapped to the CPU port(s).

Fixes: b8f126a8d543 ("net-next: dsa: add dsa support for Mediatek MT7530 switch")
Signed-off-by: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>
Reviewed-by: Vladimir Oltean <olteanv@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Stable-dep-of: e8bf353577f3 ("net: dsa: mt7530: fix link-local frames that ingress vlan filtering ports")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/dsa/mt7530.c | 4 ++++
 drivers/net/dsa/mt7530.h | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 252e8eaa92767..30570b9dc88f2 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -1000,6 +1000,10 @@ mt753x_trap_frames(struct mt7530_priv *priv)
 	mt7530_rmw(priv, MT753X_BPC, MT753X_BPDU_PORT_FW_MASK,
 		   MT753X_BPDU_CPU_ONLY);
 
+	/* Trap 802.1X PAE frames to the CPU port(s) */
+	mt7530_rmw(priv, MT753X_BPC, MT753X_PAE_PORT_FW_MASK,
+		   MT753X_PAE_PORT_FW(MT753X_BPDU_CPU_ONLY));
+
 	/* Trap LLDP frames with :0E MAC DA to the CPU port(s) */
 	mt7530_rmw(priv, MT753X_RGAC2, MT753X_R0E_PORT_FW_MASK,
 		   MT753X_R0E_PORT_FW(MT753X_BPDU_CPU_ONLY));
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index 8cee462d5f1cb..2c895f35383e2 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -65,6 +65,8 @@ enum mt753x_id {
 /* Registers for BPDU and PAE frame control*/
 #define MT753X_BPC			0x24
 #define  MT753X_BPDU_PORT_FW_MASK	GENMASK(2, 0)
+#define  MT753X_PAE_PORT_FW_MASK	GENMASK(18, 16)
+#define  MT753X_PAE_PORT_FW(x)		FIELD_PREP(MT753X_PAE_PORT_FW_MASK, x)
 
 /* Register for :03 and :0E MAC DA frame control */
 #define MT753X_RGAC2			0x2c
-- 
2.43.0