[PATCH net-next 27/30] net: dsa: mt7530: introduce BPDU trapping for MT7530 switch

[arinc9.unal at gmail.com]

From: Arınç ÜNAL <arinc.unal at arinc9.com>

The MT753X switches are capable of trapping certain frames. Introduce
trapping BPDUs to the CPU port for the MT7530 switch.

BPDUs will be trapped to the numerically smallest CPU port which is affine
to the DSA conduit interface that is set up. The BPDUs won't necessarily be
trapped to the CPU port the user port, which these BPDUs are received from,
is affine to.

Tested-by: Arınç ÜNAL <arinc.unal at arinc9.com>
Signed-off-by: Arınç ÜNAL <arinc.unal at arinc9.com>
---
 drivers/net/dsa/mt7530.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index cd16911fcb01..2fb4b0bc6335 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -2223,6 +2223,10 @@ mt7530_setup(struct dsa_switch *ds)
 	val |= MHWTRAP_MANUAL;
 	mt7530_write(priv, MT7530_MHWTRAP, val);
 
+	/* Trap BPDUs to the CPU port */
+	mt7530_rmw(priv, MT753X_BPC, MT753X_BPDU_PORT_FW_MASK,
+		   MT753X_BPDU_CPU_ONLY);
+
 	/* Enable and reset MIB counters */
 	mt7530_mib_reset(ds);
 
-- 
2.39.2