[PATCH 5.15 25/71] net: dsa: mt7530: fix mirroring frames received on local port

Greg Kroah-Hartman
2024-04-23T21:46:37Z

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

[ Upstream commit d59cf049c8378677053703e724808836f180888e ]

This switch intellectual property provides a bit on the ARL global control
register which controls allowing mirroring frames which are received on the
local port (monitor port). This bit is unset after reset.

This ability must be enabled to fully support the port mirroring feature on
this switch intellectual property.

Therefore, this patch fixes the traffic not being reflected on a port,
which would be configured like below:

tc qdisc add dev swp0 clsact

tc filter add dev swp0 ingress matchall skip_sw \
action mirred egress mirror dev swp0

As a side note, this configuration provides the hairpinning feature for a
single port.

Fixes: 37feab6076aa ("net: dsa: mt7530: add support for port mirroring")
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/dsa/mt7530.c | 6 ++++++
drivers/net/dsa/mt7530.h | 4 ++++
2 files changed, 10 insertions(+)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index f291d1e70f807..053f1b4aa324c 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -2437,6 +2437,9 @@ mt7530_setup(struct dsa_switch *ds)
PVC_EG_TAG(MT7530_VLAN_EG_CONSISTENT));
}

+ /* Allow mirroring frames received on the local port (monitor port). */
+ mt7530_set(priv, MT753X_AGC, LOCAL_EN);
+
/* Setup VLAN ID 0 for VLAN-unaware bridges */
ret = mt7530_setup_vlan0(priv);
if (ret)
@@ -2553,6 +2556,9 @@ mt7531_setup_common(struct dsa_switch *ds)
PVC_EG_TAG(MT7530_VLAN_EG_CONSISTENT));
}

+ /* Allow mirroring frames received on the local port (monitor port). */
+ mt7530_set(priv, MT753X_AGC, LOCAL_EN);
+
/* Flush the FDB table */
ret = mt7530_fdb_cmd(priv, MT7530_FDB_FLUSH, NULL);
if (ret < 0)
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index 299a26ad5809c..0247a58d5554c 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -32,6 +32,10 @@ enum mt753x_id {
#define SYSC_REG_RSTCTRL 0x34
#define RESET_MCM BIT(2)

+/* Register for ARL global control */
+#define MT753X_AGC 0xc
+#define LOCAL_EN BIT(7)
+
/* Registers to mac forward control for unknown frames */
#define MT7530_MFC 0x10
#define BC_FFP(x) (((x) & 0xff) << 24)
--
2.43.0