[PATCH net-next v2 0/4] mt7530 software fallback bridging fix

[PATCH net-next v2 0/4] mt7530 software fallback bridging fix

[DENG Qingfang]

DSA core has gained software fallback support since commit 2f5dc00f7a3e
("net: bridge: switchdev: let drivers inform which bridge ports are
offloaded"), but it does not work properly on mt7530. This patch series
fixes the issues.

DENG Qingfang (4):
  net: dsa: mt7530: enable assisted learning on CPU port
  net: dsa: mt7530: use independent VLAN learning on VLAN-unaware
    bridges
  net: dsa: mt7530: set STP state on filter ID 1
  net: dsa: mt7530: always install FDB entries with IVL and FID 1

 drivers/net/dsa/mt7530.c | 88 ++++++++++++++++++++++++++++------------
 drivers/net/dsa/mt7530.h | 14 +++++--
 2 files changed, 72 insertions(+), 30 deletions(-)

-- 
2.25.1

[PATCH net-next v2 1/4] net: dsa: mt7530: enable assisted learning on CPU port

[DENG Qingfang]

Consider the following bridge configuration, where bond0 is not
offloaded:

         +-- br0 --+
        / /   |     \
       / /    |      \
      /  |    |     bond0
     /   |    |     /   \
   swp0 swp1 swp2 swp3 swp4
     .        .       .
     .        .       .
     A        B       C

Address learning is enabled on offloaded ports (swp0~2) and the CPU
port, so when client A sends a packet to C, the following will happen:

1. The switch learns that client A can be reached at swp0.
2. The switch probably already knows that client C can be reached at the
   CPU port, so it forwards the packet to the CPU.
3. The bridge core knows client C can be reached at bond0, so it
   forwards the packet back to the switch.
4. The switch learns that client A can be reached at the CPU port.
5. The switch forwards the packet to either swp3 or swp4, according to
   the packet's tag.

That makes client A's MAC address flap between swp0 and the CPU port. If
client B sends a packet to A, it is possible that the packet is
forwarded to the CPU. With offload_fwd_mark = 1, the bridge core won't
forward it back to the switch, resulting in packet loss.

As we have the assisted_learning_on_cpu_port in DSA core now, enable
that and disable hardware learning on the CPU port.

Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Reviewed-by: Vladimir Oltean <oltean@gmail.com>
---
v1 -> v2: no changes.

 drivers/net/dsa/mt7530.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index b6e0b347947e..abe57b04fc39 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -2046,6 +2046,7 @@ mt7530_setup(struct dsa_switch *ds)
 	 * as two netdev instances.
 	 */
 	dn = dsa_to_port(ds, MT7530_CPU_PORT)->master->dev.of_node->parent;
+	ds->assisted_learning_on_cpu_port = true;
 	ds->mtu_enforcement_ingress = true;
 
 	if (priv->id == ID_MT7530) {
@@ -2116,15 +2117,15 @@ mt7530_setup(struct dsa_switch *ds)
 		mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK,
 			   PCR_MATRIX_CLR);
 
+		/* Disable learning by default on all ports */
+		mt7530_set(priv, MT7530_PSC_P(i), SA_DIS);
+
 		if (dsa_is_cpu_port(ds, i)) {
 			ret = mt753x_cpu_port_enable(ds, i);
 			if (ret)
 				return ret;
 		} else {
 			mt7530_port_disable(ds, i);
-
-			/* Disable learning by default on all user ports */
-			mt7530_set(priv, MT7530_PSC_P(i), SA_DIS);
 		}
 		/* Enable consistent egress tag */
 		mt7530_rmw(priv, MT7530_PVC_P(i), PVC_EG_TAG_MASK,
@@ -2281,6 +2282,9 @@ mt7531_setup(struct dsa_switch *ds)
 		mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK,
 			   PCR_MATRIX_CLR);
 
+		/* Disable learning by default on all ports */
+		mt7530_set(priv, MT7530_PSC_P(i), SA_DIS);
+
 		mt7530_set(priv, MT7531_DBG_CNT(i), MT7531_DIS_CLR);
 
 		if (dsa_is_cpu_port(ds, i)) {
@@ -2289,9 +2293,6 @@ mt7531_setup(struct dsa_switch *ds)
 				return ret;
 		} else {
 			mt7530_port_disable(ds, i);
-
-			/* Disable learning by default on all user ports */
-			mt7530_set(priv, MT7530_PSC_P(i), SA_DIS);
 		}
 
 		/* Enable consistent egress tag */
@@ -2299,6 +2300,7 @@ mt7531_setup(struct dsa_switch *ds)
 			   PVC_EG_TAG(MT7530_VLAN_EG_CONSISTENT));
 	}
 
+	ds->assisted_learning_on_cpu_port = true;
 	ds->mtu_enforcement_ingress = true;
 
 	/* Flush the FDB table */
-- 
2.25.1

[PATCH net-next v2 2/4] net: dsa: mt7530: use independent VLAN learning on VLAN-unaware bridges

[DENG Qingfang]

Consider the following bridge configuration, where bond0 is not
offloaded:

         +-- br0 --+
        / /   |     \
       / /    |      \
      /  |    |     bond0
     /   |    |     /   \
   swp0 swp1 swp2 swp3 swp4
     .        .       .
     .        .       .
     A        B       C

Ideally, when the switch receives a packet from swp3 or swp4, it should
forward the packet to the CPU, according to the port matrix and unknown
unicast flood settings.

But packet loss will happen if the destination address is at one of the
offloaded ports (swp0~2). For example, when client C sends a packet to
A, the FDB lookup will indicate that it should be forwarded to swp0, but
the port matrix of swp3 and swp4 is configured to only allow the CPU to
be its destination, so it is dropped.

However, this issue does not happen if the bridge is VLAN-aware. That is
because VLAN-aware bridges use independent VLAN learning, i.e. use VID
for FDB lookup, on offloaded ports. As swp3 and swp4 are not offloaded,
shared VLAN learning with default filter ID of 0 is used instead. So the
lookup for A with filter ID 0 never hits and the packet can be forwarded
to the CPU.

In the current code, only two combinations were used to toggle user
ports' VLAN awareness: one is PCR.PORT_VLAN set to port matrix mode with
PVC.VLAN_ATTR set to transparent port, the other is PCR.PORT_VLAN set to
security mode with PVC.VLAN_ATTR set to user port.

It turns out that only PVC.VLAN_ATTR contributes to VLAN awareness, and
port matrix mode just skips the VLAN table lookup. The reference manual
is somehow misleading when describing PORT_VLAN modes. It states that
PORT_MEM (VLAN port member) is used for destination if the VLAN table
lookup hits, but actually **PORT_MEM & PORT_MATRIX** (bitwise AND of
VLAN port member and port matrix) is used instead, which means we can
have two or more separate VLAN-aware bridges with the same PVID and
traffic won't leak between them.

Therefore, to solve this, enable independent VLAN learning with PVID 0
on VLAN-unaware bridges, by setting their PCR.PORT_VLAN to fallback
mode, while leaving standalone ports in port matrix mode. The CPU port
is always set to fallback mode to serve those bridges.

During testing, it is found that FDB lookup with filter ID of 0 will
also hit entries with VID 0 even with independent VLAN learning. To
avoid that, install all VLANs with filter ID of 1.

Signed-off-by: DENG Qingfang <dqfext@gmail.com>
---
v1 -> v2: use FID enum instead of hardcoding.

 drivers/net/dsa/mt7530.c | 71 +++++++++++++++++++++++++++++-----------
 drivers/net/dsa/mt7530.h |  9 ++++-
 2 files changed, 59 insertions(+), 21 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index abe57b04fc39..606a9f4db579 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -1021,6 +1021,10 @@ mt753x_cpu_port_enable(struct dsa_switch *ds, int port)
 	mt7530_write(priv, MT7530_PCR_P(port),
 		     PCR_MATRIX(dsa_user_ports(priv->ds)));
 
+	/* Set to fallback mode for independent VLAN learning */
+	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_PORT_VLAN_MASK,
+		   MT7530_PORT_FALLBACK_MODE);
+
 	return 0;
 }
 
@@ -1229,6 +1233,10 @@ mt7530_port_bridge_join(struct dsa_switch *ds, int port,
 			   PCR_MATRIX_MASK, PCR_MATRIX(port_bitmap));
 	priv->ports[port].pm |= PCR_MATRIX(port_bitmap);
 
+	/* Set to fallback mode for independent VLAN learning */
+	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_PORT_VLAN_MASK,
+		   MT7530_PORT_FALLBACK_MODE);
+
 	mutex_unlock(&priv->reg_mutex);
 
 	return 0;
@@ -1241,16 +1249,21 @@ mt7530_port_set_vlan_unaware(struct dsa_switch *ds, int port)
 	bool all_user_ports_removed = true;
 	int i;
 
-	/* When a port is removed from the bridge, the port would be set up
-	 * back to the default as is at initial boot which is a VLAN-unaware
-	 * port.
+	/* This is called after .port_bridge_leave when leaving a VLAN-aware
+	 * bridge. Don't set standalone ports to fallback mode.
 	 */
-	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_PORT_VLAN_MASK,
-		   MT7530_PORT_MATRIX_MODE);
+	if (dsa_to_port(ds, port)->bridge_dev)
+		mt7530_rmw(priv, MT7530_PCR_P(port), PCR_PORT_VLAN_MASK,
+			   MT7530_PORT_FALLBACK_MODE);
+
 	mt7530_rmw(priv, MT7530_PVC_P(port), VLAN_ATTR_MASK | PVC_EG_TAG_MASK,
 		   VLAN_ATTR(MT7530_VLAN_TRANSPARENT) |
 		   PVC_EG_TAG(MT7530_VLAN_EG_CONSISTENT));
 
+	/* Set PVID to 0 */
+	mt7530_rmw(priv, MT7530_PPBV1_P(port), G0_PORT_VID_MASK,
+		   G0_PORT_VID_DEF);
+
 	for (i = 0; i < MT7530_NUM_PORTS; i++) {
 		if (dsa_is_user_port(ds, i) &&
 		    dsa_port_is_vlan_filtering(dsa_to_port(ds, i))) {
@@ -1276,15 +1289,14 @@ mt7530_port_set_vlan_aware(struct dsa_switch *ds, int port)
 	struct mt7530_priv *priv = ds->priv;
 
 	/* Trapped into security mode allows packet forwarding through VLAN
-	 * table lookup. CPU port is set to fallback mode to let untagged
-	 * frames pass through.
+	 * table lookup.
 	 */
-	if (dsa_is_cpu_port(ds, port))
-		mt7530_rmw(priv, MT7530_PCR_P(port), PCR_PORT_VLAN_MASK,
-			   MT7530_PORT_FALLBACK_MODE);
-	else
+	if (dsa_is_user_port(ds, port)) {
 		mt7530_rmw(priv, MT7530_PCR_P(port), PCR_PORT_VLAN_MASK,
 			   MT7530_PORT_SECURITY_MODE);
+		mt7530_rmw(priv, MT7530_PPBV1_P(port), G0_PORT_VID_MASK,
+			   G0_PORT_VID(priv->ports[port].pvid));
+	}
 
 	/* Set the port as a user port which is to be able to recognize VID
 	 * from incoming packets before fetching entry within the VLAN table.
@@ -1329,6 +1341,13 @@ mt7530_port_bridge_leave(struct dsa_switch *ds, int port,
 			   PCR_MATRIX(BIT(MT7530_CPU_PORT)));
 	priv->ports[port].pm = PCR_MATRIX(BIT(MT7530_CPU_PORT));
 
+	/* When a port is removed from the bridge, the port would be set up
+	 * back to the default as is at initial boot which is a VLAN-unaware
+	 * port.
+	 */
+	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_PORT_VLAN_MASK,
+		   MT7530_PORT_MATRIX_MODE);
+
 	mutex_unlock(&priv->reg_mutex);
 }
 
@@ -1511,7 +1530,8 @@ mt7530_hw_vlan_add(struct mt7530_priv *priv,
 	/* Validate the entry with independent learning, create egress tag per
 	 * VLAN and joining the port as one of the port members.
 	 */
-	val = IVL_MAC | VTAG_EN | PORT_MEM(new_members) | VLAN_VALID;
+	val = IVL_MAC | VTAG_EN | PORT_MEM(new_members) | FID(FID_BRIDGED) |
+	      VLAN_VALID;
 	mt7530_write(priv, MT7530_VAWD1, val);
 
 	/* Decide whether adding tag or not for those outgoing packets from the
@@ -1601,9 +1621,13 @@ mt7530_port_vlan_add(struct dsa_switch *ds, int port,
 	mt7530_hw_vlan_update(priv, vlan->vid, &new_entry, mt7530_hw_vlan_add);
 
 	if (pvid) {
-		mt7530_rmw(priv, MT7530_PPBV1_P(port), G0_PORT_VID_MASK,
-			   G0_PORT_VID(vlan->vid));
 		priv->ports[port].pvid = vlan->vid;
+
+		/* Only configure PVID if VLAN filtering is enabled */
+		if (dsa_port_is_vlan_filtering(dsa_to_port(ds, port)))
+			mt7530_rmw(priv, MT7530_PPBV1_P(port),
+				   G0_PORT_VID_MASK,
+				   G0_PORT_VID(vlan->vid));
 	}
 
 	mutex_unlock(&priv->reg_mutex);
@@ -1617,11 +1641,9 @@ mt7530_port_vlan_del(struct dsa_switch *ds, int port,
 {
 	struct mt7530_hw_vlan_entry target_entry;
 	struct mt7530_priv *priv = ds->priv;
-	u16 pvid;
 
 	mutex_lock(&priv->reg_mutex);
 
-	pvid = priv->ports[port].pvid;
 	mt7530_hw_vlan_entry_init(&target_entry, port, 0);
 	mt7530_hw_vlan_update(priv, vlan->vid, &target_entry,
 			      mt7530_hw_vlan_del);
@@ -1629,11 +1651,12 @@ mt7530_port_vlan_del(struct dsa_switch *ds, int port,
 	/* PVID is being restored to the default whenever the PVID port
 	 * is being removed from the VLAN.
 	 */
-	if (pvid == vlan->vid)
-		pvid = G0_PORT_VID_DEF;
+	if (priv->ports[port].pvid == vlan->vid) {
+		priv->ports[port].pvid = G0_PORT_VID_DEF;
+		mt7530_rmw(priv, MT7530_PPBV1_P(port), G0_PORT_VID_MASK,
+			   G0_PORT_VID_DEF);
+	}
 
-	mt7530_rmw(priv, MT7530_PPBV1_P(port), G0_PORT_VID_MASK, pvid);
-	priv->ports[port].pvid = pvid;
 
 	mutex_unlock(&priv->reg_mutex);
 
@@ -2126,6 +2149,10 @@ mt7530_setup(struct dsa_switch *ds)
 				return ret;
 		} else {
 			mt7530_port_disable(ds, i);
+
+			/* Set default PVID to 0 on all user ports */
+			mt7530_rmw(priv, MT7530_PPBV1_P(i), G0_PORT_VID_MASK,
+				   G0_PORT_VID_DEF);
 		}
 		/* Enable consistent egress tag */
 		mt7530_rmw(priv, MT7530_PVC_P(i), PVC_EG_TAG_MASK,
@@ -2293,6 +2320,10 @@ mt7531_setup(struct dsa_switch *ds)
 				return ret;
 		} else {
 			mt7530_port_disable(ds, i);
+
+			/* Set default PVID to 0 on all user ports */
+			mt7530_rmw(priv, MT7530_PPBV1_P(i), G0_PORT_VID_MASK,
+				   G0_PORT_VID_DEF);
 		}
 
 		/* Enable consistent egress tag */
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index b19b389ff10a..d44640bbd865 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -148,11 +148,18 @@ enum mt7530_vlan_cmd {
 #define  VTAG_EN			BIT(28)
 /* VLAN Member Control */
 #define  PORT_MEM(x)			(((x) & 0xff) << 16)
+/* Filter ID */
+#define  FID(x)				(((x) & 0x7) << 1)
 /* VLAN Entry Valid */
 #define  VLAN_VALID			BIT(0)
 #define  PORT_MEM_SHFT			16
 #define  PORT_MEM_MASK			0xff
 
+enum mt7530_fid {
+	FID_STANDALONE = 0,
+	FID_BRIDGED = 1,
+};
+
 #define MT7530_VAWD2			0x98
 /* Egress Tag Control */
 #define  ETAG_CTRL_P(p, x)		(((x) & 0x3) << ((p) << 1))
@@ -247,7 +254,7 @@ enum mt7530_vlan_port_attr {
 #define MT7530_PPBV1_P(x)		(0x2014 + ((x) * 0x100))
 #define  G0_PORT_VID(x)			(((x) & 0xfff) << 0)
 #define  G0_PORT_VID_MASK		G0_PORT_VID(0xfff)
-#define  G0_PORT_VID_DEF		G0_PORT_VID(1)
+#define  G0_PORT_VID_DEF		G0_PORT_VID(0)
 
 /* Register for port MAC control register */
 #define MT7530_PMCR_P(x)		(0x3000 + ((x) * 0x100))
-- 
2.25.1

[PATCH net-next v2 3/4] net: dsa: mt7530: set STP state on filter ID 1

[DENG Qingfang]

As filter ID 1 is the only one used for bridges, set STP state on it.

Signed-off-by: DENG Qingfang <dqfext@gmail.com>
---
v1 -> v2: use FID enum instead of hardcoding.

 drivers/net/dsa/mt7530.c | 3 ++-
 drivers/net/dsa/mt7530.h | 4 ++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 606a9f4db579..9b39ccd9dd4c 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -1147,7 +1147,8 @@ mt7530_stp_state_set(struct dsa_switch *ds, int port, u8 state)
 		break;
 	}
 
-	mt7530_rmw(priv, MT7530_SSP_P(port), FID_PST_MASK, stp_state);
+	mt7530_rmw(priv, MT7530_SSP_P(port), FID_PST_MASK(FID_BRIDGED),
+		   FID_PST(FID_BRIDGED, stp_state));
 }
 
 static int
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index d44640bbd865..5b70ccef9459 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -186,8 +186,8 @@ enum mt7530_vlan_egress_attr {
 
 /* Register for port STP state control */
 #define MT7530_SSP_P(x)			(0x2000 + ((x) * 0x100))
-#define  FID_PST(x)			((x) & 0x3)
-#define  FID_PST_MASK			FID_PST(0x3)
+#define  FID_PST(fid, state)		(((state) & 0x3) << ((fid) * 2))
+#define  FID_PST_MASK(fid)		FID_PST(fid, 0x3)
 
 enum mt7530_stp_state {
 	MT7530_STP_DISABLED = 0,
-- 
2.25.1

[PATCH net-next v2 4/4] net: dsa: mt7530: always install FDB entries with IVL and FID 1

[DENG Qingfang]

This reverts commit 7e777021780e ("mt7530 mt7530_fdb_write only set ivl
bit vid larger than 1").

Before this series, the default value of all ports' PVID is 1, which is
copied into the FDB entry, even if the ports are VLAN unaware. So
`bridge fdb show` will show entries like `dev swp0 vlan 1 self` even on
a VLAN-unaware bridge.

The blamed commit does not solve that issue completely, instead it may
cause a new issue that FDB is inaccessible in a VLAN-aware bridge with
PVID 1.

This series sets PVID to 0 on VLAN-unaware ports, so `bridge fdb show`
will no longer print `vlan 1` on VLAN-unaware bridges, and that special
case in fdb_write is not required anymore.

Set FDB entries' filter ID to 1 to match the VLAN table.

Signed-off-by: DENG Qingfang <dqfext@gmail.com>
---
v1 -> v2: use FID enum instead of hardcoding.

 drivers/net/dsa/mt7530.c | 4 ++--
 drivers/net/dsa/mt7530.h | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 9b39ccd9dd4c..385e169080d9 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -366,8 +366,8 @@ mt7530_fdb_write(struct mt7530_priv *priv, u16 vid,
 	int i;
 
 	reg[1] |= vid & CVID_MASK;
-	if (vid > 1)
-		reg[1] |= ATA2_IVL;
+	reg[1] |= ATA2_IVL;
+	reg[1] |= ATA2_FID(FID_BRIDGED);
 	reg[2] |= (aging & AGE_TIMER_MASK) << AGE_TIMER;
 	reg[2] |= (port_mask & PORT_MAP_MASK) << PORT_MAP;
 	/* STATIC_ENT indicate that entry is static wouldn't
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index 5b70ccef9459..4a91d80f51bb 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -80,6 +80,7 @@ enum mt753x_bpdu_port_fw {
 #define  STATIC_ENT			3
 #define MT7530_ATA2			0x78
 #define  ATA2_IVL			BIT(15)
+#define  ATA2_FID(x)			(((x) & 0x7) << 12)
 
 /* Register for address table write data */
 #define MT7530_ATWD			0x7c
-- 
2.25.1

Re: [PATCH net-next v2 2/4] net: dsa: mt7530: use independent VLAN learning on VLAN-unaware bridges

[Vladimir Oltean]

On Wed, Aug 04, 2021 at 12:04:02AM +0800, DENG Qingfang wrote:
> Consider the following bridge configuration, where bond0 is not
> offloaded:
> 
>          +-- br0 --+
>         / /   |     \
>        / /    |      \
>       /  |    |     bond0
>      /   |    |     /   \
>    swp0 swp1 swp2 swp3 swp4
>      .        .       .
>      .        .       .
>      A        B       C
> 
> Ideally, when the switch receives a packet from swp3 or swp4, it should
> forward the packet to the CPU, according to the port matrix and unknown
> unicast flood settings.
> 
> But packet loss will happen if the destination address is at one of the
> offloaded ports (swp0~2). For example, when client C sends a packet to
> A, the FDB lookup will indicate that it should be forwarded to swp0, but
> the port matrix of swp3 and swp4 is configured to only allow the CPU to
> be its destination, so it is dropped.
> 
> However, this issue does not happen if the bridge is VLAN-aware. That is
> because VLAN-aware bridges use independent VLAN learning, i.e. use VID
> for FDB lookup, on offloaded ports. As swp3 and swp4 are not offloaded,
> shared VLAN learning with default filter ID of 0 is used instead. So the
> lookup for A with filter ID 0 never hits and the packet can be forwarded
> to the CPU.
> 
> In the current code, only two combinations were used to toggle user
> ports' VLAN awareness: one is PCR.PORT_VLAN set to port matrix mode with
> PVC.VLAN_ATTR set to transparent port, the other is PCR.PORT_VLAN set to
> security mode with PVC.VLAN_ATTR set to user port.
> 
> It turns out that only PVC.VLAN_ATTR contributes to VLAN awareness, and
> port matrix mode just skips the VLAN table lookup. The reference manual
> is somehow misleading when describing PORT_VLAN modes. It states that
> PORT_MEM (VLAN port member) is used for destination if the VLAN table
> lookup hits, but actually **PORT_MEM & PORT_MATRIX** (bitwise AND of
> VLAN port member and port matrix) is used instead, which means we can
> have two or more separate VLAN-aware bridges with the same PVID and
> traffic won't leak between them.
> 
> Therefore, to solve this, enable independent VLAN learning with PVID 0
> on VLAN-unaware bridges, by setting their PCR.PORT_VLAN to fallback
> mode, while leaving standalone ports in port matrix mode. The CPU port
> is always set to fallback mode to serve those bridges.
> 
> During testing, it is found that FDB lookup with filter ID of 0 will
> also hit entries with VID 0 even with independent VLAN learning. To
> avoid that, install all VLANs with filter ID of 1.
> 
> Signed-off-by: DENG Qingfang <dqfext@gmail.com>
> ---
> v1 -> v2: use FID enum instead of hardcoding.

Reviewed-by: Vladimir Oltean <olteanv@gmail.com>

> @@ -1629,11 +1651,12 @@ mt7530_port_vlan_del(struct dsa_switch *ds, int port,
>  	/* PVID is being restored to the default whenever the PVID port
>  	 * is being removed from the VLAN.
>  	 */
> -	if (pvid == vlan->vid)
> -		pvid = G0_PORT_VID_DEF;
> +	if (priv->ports[port].pvid == vlan->vid) {
> +		priv->ports[port].pvid = G0_PORT_VID_DEF;
> +		mt7530_rmw(priv, MT7530_PPBV1_P(port), G0_PORT_VID_MASK,
> +			   G0_PORT_VID_DEF);
> +	}

After this patch set gets merged, can you also please take a look at the
following:

Documentation/networking/switchdev.rst says:

When the bridge has VLAN filtering enabled and a PVID is not configured on the
ingress port, untagged and 802.1p tagged packets must be dropped. When the bridge
has VLAN filtering enabled and a PVID exists on the ingress port, untagged and
priority-tagged packets must be accepted and forwarded according to the
bridge's port membership of the PVID VLAN. When the bridge has VLAN filtering
disabled, the presence/lack of a PVID should not influence the packet
forwarding decision.

I'm not sure if this happens or not with mt7530, since the driver
attempts to change the pvid back to 0. You are not changing this
behavior in this series, so no reason to deal with it as part of it.

>  
> -	mt7530_rmw(priv, MT7530_PPBV1_P(port), G0_PORT_VID_MASK, pvid);
> -	priv->ports[port].pvid = pvid;
>  
>  	mutex_unlock(&priv->reg_mutex);
>  

Re: [PATCH net-next v2 3/4] net: dsa: mt7530: set STP state on filter ID 1

[Vladimir Oltean]

On Wed, Aug 04, 2021 at 12:04:03AM +0800, DENG Qingfang wrote:
> As filter ID 1 is the only one used for bridges, set STP state on it.
> 
> Signed-off-by: DENG Qingfang <dqfext@gmail.com>
> ---

Reviewed-by: Vladimir Oltean <olteanv@gmail.com>

Re: [PATCH net-next v2 4/4] net: dsa: mt7530: always install FDB entries with IVL and FID 1

[Vladimir Oltean]

On Wed, Aug 04, 2021 at 12:04:04AM +0800, DENG Qingfang wrote:
> This reverts commit 7e777021780e ("mt7530 mt7530_fdb_write only set ivl
> bit vid larger than 1").
> 
> Before this series, the default value of all ports' PVID is 1, which is
> copied into the FDB entry, even if the ports are VLAN unaware. So
> `bridge fdb show` will show entries like `dev swp0 vlan 1 self` even on
> a VLAN-unaware bridge.
> 
> The blamed commit does not solve that issue completely, instead it may
> cause a new issue that FDB is inaccessible in a VLAN-aware bridge with
> PVID 1.
> 
> This series sets PVID to 0 on VLAN-unaware ports, so `bridge fdb show`
> will no longer print `vlan 1` on VLAN-unaware bridges, and that special
> case in fdb_write is not required anymore.
> 
> Set FDB entries' filter ID to 1 to match the VLAN table.
> 
> Signed-off-by: DENG Qingfang <dqfext@gmail.com>
> ---

The way FDB entries are installed now makes a lot more intuitive sense.

Re: [PATCH net-next v2 2/4] net: dsa: mt7530: use independent VLAN learning on VLAN-unaware bridges

[DENG Qingfang]

On Tue, Aug 03, 2021 at 07:48:53PM +0300, Vladimir Oltean wrote:
> After this patch set gets merged, can you also please take a look at the
> following:
> 
> Documentation/networking/switchdev.rst says:
> 
> When the bridge has VLAN filtering enabled and a PVID is not configured on the
> ingress port, untagged and 802.1p tagged packets must be dropped. When the bridge
> has VLAN filtering enabled and a PVID exists on the ingress port, untagged and
> priority-tagged packets must be accepted and forwarded according to the
> bridge's port membership of the PVID VLAN. When the bridge has VLAN filtering
> disabled, the presence/lack of a PVID should not influence the packet
> forwarding decision.
> 
> I'm not sure if this happens or not with mt7530, since the driver
> attempts to change the pvid back to 0. You are not changing this
> behavior in this series, so no reason to deal with it as part of it.
> 

There is PVC.ACC_FRM which controls the acceptable frame type.
Currently the driver does not use it, so untagged and priority-tagged frames
can get into a VLAN-aware port without a PVID.

Re: [PATCH net-next v2 4/4] net: dsa: mt7530: always install FDB entries with IVL and FID 1

[DENG Qingfang]

On Tue, Aug 03, 2021 at 07:51:38PM +0300, Vladimir Oltean wrote:
> 
> The way FDB entries are installed now makes a lot more intuitive sense.

Did you forget to add the Reviewed-by tag?

Re: [PATCH net-next v2 4/4] net: dsa: mt7530: always install FDB entries with IVL and FID 1

[Vladimir Oltean]

On Wed, Aug 04, 2021 at 01:53:54AM +0800, DENG Qingfang wrote:
> On Tue, Aug 03, 2021 at 07:51:38PM +0300, Vladimir Oltean wrote:
> > 
> > The way FDB entries are installed now makes a lot more intuitive sense.
> 
> Did you forget to add the Reviewed-by tag?

Yeah, in fact I did. I was in a rush and by the time I figured that
I didn't do that, I had already left home.

Still, in fact the patch is obviously correct, which is nice. Standalone
ports never learn and the FDB lookup will always miss because it's in
FID 0 (a separate FID compared to the bridge ports) and there is no FDB
entry there. Packets will always be flooded to their only possible
destination, the CPU port. Ports under VLAN-unaware bridges always use
IVL and learn using the pvid, which is zero, and which happily coincides
with the VID which the bridge uses to install VLAN-unaware FDB entries.
Ports under VLAN-aware bridges again use IVL but the VID is taken from
the packet not just from the pvid, so the VID will be >= 1 there. Again
it coincides with the vid that the bridge uses to offload FDB entries.
Nice, I really like it, it is really simple.

Reviewed-by: Vladimir Oltean <olteanv@gmail.com>

Re: [PATCH net-next v2 0/4] mt7530 software fallback bridging fix

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (refs/heads/master):

On Wed,  4 Aug 2021 00:04:00 +0800 you wrote:
> DSA core has gained software fallback support since commit 2f5dc00f7a3e
> ("net: bridge: switchdev: let drivers inform which bridge ports are
> offloaded"), but it does not work properly on mt7530. This patch series
> fixes the issues.
> 
> DENG Qingfang (4):
>   net: dsa: mt7530: enable assisted learning on CPU port
>   net: dsa: mt7530: use independent VLAN learning on VLAN-unaware
>     bridges
>   net: dsa: mt7530: set STP state on filter ID 1
>   net: dsa: mt7530: always install FDB entries with IVL and FID 1
> 
> [...]

Here is the summary with links:
  - [net-next,v2,1/4] net: dsa: mt7530: enable assisted learning on CPU port
    https://git.kernel.org/netdev/net-next/c/0b69c54c74bc
  - [net-next,v2,2/4] net: dsa: mt7530: use independent VLAN learning on VLAN-unaware bridges
    https://git.kernel.org/netdev/net-next/c/6087175b7991
  - [net-next,v2,3/4] net: dsa: mt7530: set STP state on filter ID 1
    https://git.kernel.org/netdev/net-next/c/a9e3f62dff3c
  - [net-next,v2,4/4] net: dsa: mt7530: always install FDB entries with IVL and FID 1
    https://git.kernel.org/netdev/net-next/c/73c447cacbbd

You are awesome, thank you!
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