net: dsa: rtl8366: Fix VLAN semantics

The RTL8366 would not handle adding new members (ports) to
a VLAN: the code assumed that ->port_vlan_add() was only
called once for a single port. When intializing the
switch with .configure_vlan_while_not_filtering set to
true, the function is called numerous times for adding
all ports to VLAN1, which was something the code could
not handle.

Alter rtl8366_set_vlan() to just |= new members and
untagged flags to 4k and MC VLAN table entries alike.
This makes it possible to just add new ports to a
VLAN.

Put in some helpful debug code that can be used to find
any further bugs here.

Cc: DENG Qingfang <dqfext@gmail.com>
Cc: Mauri Sandberg <sandberg@mailfence.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Fixes: d8652956 ("net: dsa: realtek-smi: Add Realtek SMI driver")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/rtl8366.c

@@ -43,18 +43,26 @@ int rtl8366_set_vlan(struct realtek_smi *smi, int vid, u32 member,
 	int ret;
 	int i;
 
+	dev_dbg(smi->dev,
+		"setting VLAN%d 4k members: 0x%02x, untagged: 0x%02x\n",
+		vid, member, untag);
+
 	/* Update the 4K table */
 	ret = smi->ops->get_vlan_4k(smi, vid, &vlan4k);
 	if (ret)
 		return ret;
 
-	vlan4k.member = member;
-	vlan4k.untag = untag;
+	vlan4k.member |= member;
+	vlan4k.untag |= untag;
 	vlan4k.fid = fid;
 	ret = smi->ops->set_vlan_4k(smi, &vlan4k);
 	if (ret)
 		return ret;
 
+	dev_dbg(smi->dev,
+		"resulting VLAN%d 4k members: 0x%02x, untagged: 0x%02x\n",
+		vid, vlan4k.member, vlan4k.untag);
+
 	/* Try to find an existing MC entry for this VID */
 	for (i = 0; i < smi->num_vlan_mc; i++) {
 		struct rtl8366_vlan_mc vlanmc;
@@ -65,11 +73,16 @@ int rtl8366_set_vlan(struct realtek_smi *smi, int vid, u32 member,
 
 		if (vid == vlanmc.vid) {
 			/* update the MC entry */
-			vlanmc.member = member;
-			vlanmc.untag = untag;
+			vlanmc.member |= member;
+			vlanmc.untag |= untag;
 			vlanmc.fid = fid;
 
 			ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+
+			dev_dbg(smi->dev,
+				"resulting VLAN%d MC members: 0x%02x, untagged: 0x%02x\n",
+				vid, vlanmc.member, vlanmc.untag);
+
 			break;
 		}
 	}