From 9130c2d30c17846287b803a9803106318cbe5266 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 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 --- 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 af3744d8b6cf..8bcef4b2dd6f 100644 --- a/drivers/net/dsa/microchip/ksz8795.c +++ b/drivers/net/dsa/microchip/ksz8795.c @@ -1150,8 +1150,10 @@ 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 @@ -1751,6 +1753,11 @@ 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; }