From 3cc015794dab78b1ae12fe9ab76718c37576f6b3 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Tue, 10 Aug 2021 00:59:57 +0200 Subject: [PATCH] net: dsa: microchip: ksz8795: Use software untagging on CPU port [ Upstream commit 9130c2d30c17846287b803a9803106318cbe5266 ] On the CPU port, we can support both tagged and untagged VLANs at the same time by doing any necessary untagging in software rather than hardware. To enable that, keep the CPU port's Remove Tag flag cleared and set the dsa_switch::untag_bridge_pvid flag. Fixes: e66f840c08a2 ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver") Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/dsa/microchip/ksz8795.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c index 46ef5bc79cbd6..4bd735c5183cd 100644 --- a/drivers/net/dsa/microchip/ksz8795.c +++ b/drivers/net/dsa/microchip/ksz8795.c @@ -1109,8 +1109,10 @@ static int ksz8_port_vlan_add(struct dsa_switch *ds, int port, /* If a VLAN is added with untagged flag different from the * port's Remove Tag flag, we need to change the latter. * Ignore VID 0, which is always untagged. + * Ignore CPU port, which will always be tagged. */ - if (untagged != p->remove_tag && vlan->vid != 0) { + if (untagged != p->remove_tag && vlan->vid != 0 && + port != dev->cpu_port) { unsigned int vid; /* Reject attempts to add a VLAN that requires the @@ -1655,6 +1657,11 @@ static int ksz8_switch_init(struct ksz_device *dev) /* set the real number of ports */ dev->ds->num_ports = dev->port_cnt; + /* We rely on software untagging on the CPU port, so that we + * can support both tagged and untagged VLANs + */ + dev->ds->untag_bridge_pvid = true; + return 0; }