Subject: [PATCH 14/36] net: dsa: rtl8366: Properly clear member config

From: Linus Walleij <[email-masked]>
Date: Sat, 5 Sep 2020 12:32:33 +0200

[ Upstream commit 4ddcaf1ebb5e4e99240f29d531ee69d4244fe416 ]

When removing a port from a VLAN we are just erasing the
member config for the VLAN, which is wrong: other ports
can be using it.

Just mask off the port and only zero out the rest of the
member config once ports using of the VLAN are removed
from it.

Reported-by: Florian Fainelli <[email-masked]>
Fixes: d8652956cf37 ("net: dsa: realtek-smi: Add Realtek SMI driver")
Signed-off-by: Linus Walleij <[email-masked]>
Signed-off-by: Jakub Kicinski <[email-masked]>
---
 drivers/net/dsa/rtl8366.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/net/dsa/rtl8366.c b/drivers/net/dsa/rtl8366.c
index 1368816abaed..99cdb2f18fa2 100644
--- a/drivers/net/dsa/rtl8366.c
+++ b/drivers/net/dsa/rtl8366.c
@@ -452,13 +452,19 @@ int rtl8366_vlan_del(struct dsa_switch *ds, int port,
 				return ret;
 
 			if (vid == vlanmc.vid) {
-				/* clear VLAN member configurations */
-				vlanmc.vid = 0;
-				vlanmc.priority = 0;
-				vlanmc.member = 0;
-				vlanmc.untag = 0;
-				vlanmc.fid = 0;
-
+				/* Remove this port from the VLAN */
+				vlanmc.member &= ~BIT(port);
+				vlanmc.untag &= ~BIT(port);
+				/*
+				 * If no ports are members of this VLAN
+				 * anymore then clear the whole member
+				 * config so it can be reused.
+				 */
+				if (!vlanmc.member && vlanmc.untag) {
+					vlanmc.vid = 0;
+					vlanmc.priority = 0;
+					vlanmc.fid = 0;
+				}
 				ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
 				if (ret) {
 					dev_err(smi->dev,
-- 
2.26.2