[PATCH net] net: dsa: mt7530: fix CPU flooding and do not set CPU association

[arinc9.unal@gmail.com]

From: Richard van Schagen <richard@routerhints.com>

The original code only enables flooding on CPU port, on port 6, since
that's the last one set up. In doing so, it removes flooding on port 5,
which made so that, in order to communicate properly over port 5, a frame
had to be sent from a user port to the DSA master. Fix this.

Since CPU->port is forced via the DSA tag, connecting CPU to all user ports
of the switch breaks communication over VLAN tagged frames. Therefore,
remove the code that sets CPU assocation. This way, the CPU reverts to not
being connected to any port as soon as ".port_enable" is called.

[ arinc.unal@arinc9.com: Wrote subject and changelog ]

Tested-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Signed-off-by: Richard van Schagen <richard@routerhints.com>
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
---
 drivers/net/dsa/mt7530.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 3a15015bc409..b5ad4b4fc00c 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -997,6 +997,7 @@ mt753x_cpu_port_enable(struct dsa_switch *ds, int port)
 {
 	struct mt7530_priv *priv = ds->priv;
 	int ret;
+	u32 val;
 
 	/* Setup max capability of CPU port at first */
 	if (priv->info->cpu_port_config) {
@@ -1009,20 +1010,15 @@ mt753x_cpu_port_enable(struct dsa_switch *ds, int port)
 	mt7530_write(priv, MT7530_PVC_P(port),
 		     PORT_SPEC_TAG);
 
-	/* Disable flooding by default */
-	mt7530_rmw(priv, MT7530_MFC, BC_FFP_MASK | UNM_FFP_MASK | UNU_FFP_MASK,
-		   BC_FFP(BIT(port)) | UNM_FFP(BIT(port)) | UNU_FFP(BIT(port)));
+	/* Enable flooding on CPU */
+	val = mt7530_read(priv, MT7530_MFC);
+	val |= BC_FFP(BIT(port)) | UNM_FFP(BIT(port)) | UNU_FFP(BIT(port));
+	mt7530_write(priv, MT7530_MFC, val);
 
 	/* Set CPU port number */
 	if (priv->id == ID_MT7621)
 		mt7530_rmw(priv, MT7530_MFC, CPU_MASK, CPU_EN | CPU_PORT(port));
 
-	/* CPU port gets connected to all user ports of
-	 * the switch.
-	 */
-	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);
@@ -2204,6 +2200,9 @@ mt7530_setup(struct dsa_switch *ds)
 
 	priv->p6_interface = PHY_INTERFACE_MODE_NA;
 
+	/* Disable flooding by default */
+	mt7530_rmw(priv, MT7530_MFC, BC_FFP_MASK | UNM_FFP_MASK | UNU_FFP_MASK, 0);
+
 	/* Enable and reset MIB counters */
 	mt7530_mib_reset(ds);
 
-- 
2.37.2