Patch "net: dsa: mt7530: fix handling of BPDUs on MT7530 switch" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    net: dsa: mt7530: fix handling of BPDUs on MT7530 switch

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-dsa-mt7530-fix-handling-of-bpdus-on-mt7530-switc.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 2e05c86b050dffb6fd8178859cd8e0baf3c97a0f
Author: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>
Date:   Sat Jun 17 09:26:46 2023 +0300

    net: dsa: mt7530: fix handling of BPDUs on MT7530 switch
    
    [ Upstream commit d7c66073559386b836bded7cdc8b66ee5c049129 ]
    
    BPDUs are link-local frames, therefore they must be trapped to the CPU
    port. Currently, the MT7530 switch treats BPDUs as regular multicast
    frames, therefore flooding them to user ports. To fix this, set BPDUs to be
    trapped to the CPU port. Group this on mt7530_setup() and
    mt7531_setup_common() into mt753x_trap_frames() and call that.
    
    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>
    Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
    Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 4aa3d0cba7b84..f74d9fbd08178 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -993,6 +993,14 @@ static void mt7530_setup_port5(struct dsa_switch *ds, phy_interface_t interface)
 	mutex_unlock(&priv->reg_mutex);
 }
 
+static void
+mt753x_trap_frames(struct mt7530_priv *priv)
+{
+	/* Trap BPDUs to the CPU port(s) */
+	mt7530_rmw(priv, MT753X_BPC, MT753X_BPDU_PORT_FW_MASK,
+		   MT753X_BPDU_CPU_ONLY);
+}
+
 static int
 mt753x_cpu_port_enable(struct dsa_switch *ds, int port)
 {
@@ -2194,6 +2202,8 @@ mt7530_setup(struct dsa_switch *ds)
 
 	priv->p6_interface = PHY_INTERFACE_MODE_NA;
 
+	mt753x_trap_frames(priv);
+
 	/* Enable and reset MIB counters */
 	mt7530_mib_reset(ds);
 
@@ -2300,8 +2310,8 @@ mt7531_setup_common(struct dsa_switch *ds)
 			   BIT(cpu_dp->index));
 		break;
 	}
-	mt7530_rmw(priv, MT753X_BPC, MT753X_BPDU_PORT_FW_MASK,
-		   MT753X_BPDU_CPU_ONLY);
+
+	mt753x_trap_frames(priv);
 
 	/* Enable and reset MIB counters */
 	mt7530_mib_reset(ds);