From bd48b911c88f017a97b1943201d23d6962968d1a Mon Sep 17 00:00:00 2001
From: Tobias Waldekranz <tobias@waldekranz.com>
Date: Fri, 18 Mar 2022 21:13:21 +0100
Subject: [PATCH] net: dsa: mv88e6xxx: Ensure STU support in VLAN MSTI callback
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In the same way that we check for STU support in the MST state
callback, we should also verify it before trying to change a VLANs
MSTI membership.

Fixes: acaf4d2e36b3 ("net: dsa: mv88e6xxx: MST Offloading")
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/dsa/mv88e6xxx/chip.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index b36393ba6d49..afb9417ffca0 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -2678,6 +2678,9 @@ static int mv88e6xxx_vlan_msti_set(struct dsa_switch *ds,
 	u8 old_sid, new_sid;
 	int err;
 
+	if (!mv88e6xxx_has_stu(chip))
+		return -EOPNOTSUPP;
+
 	mv88e6xxx_reg_lock(chip);
 
 	err = mv88e6xxx_vtu_get(chip, msti->vid, &vlan);
-- 
2.11.0