From 87b0f983f66f23762921129fd35966eddc3f2dae Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Tue, 14 Apr 2020 22:36:15 +0300 Subject: net: mscc: ocelot: fix untagged packet drops when enslaving to vlan aware bridge To rehash a previous explanation given in commit 1c44ce560b4d ("net: mscc: ocelot: fix vlan_filtering when enslaving to bridge before link is up"), the switch driver operates the in a mode where a single VLAN can be transmitted as untagged on a particular egress port. That is the "native VLAN on trunk port" use case. The configuration for this native VLAN is driven in 2 ways: - Set the egress port rewriter to strip the VLAN tag for the native VID (as it is egress-untagged, after all). - Configure the ingress port to drop untagged and priority-tagged traffic, if there is no native VLAN. The intention of this setting is that a trunk port with no native VLAN should not accept untagged traffic. Since both of the above configurations for the native VLAN should only be done if VLAN awareness is requested, they are actually done from the ocelot_port_vlan_filtering function, after the basic procedure of toggling the VLAN awareness flag of the port. But there's a problem with that simplistic approach: we are trying to juggle with 2 independent variables from a single function: - Native VLAN of the port - its value is held in port->vid. - VLAN awareness state of the port - currently there are some issues here, more on that later*. The actual problem can be seen when enslaving the switch ports to a VLAN filtering bridge: 0. The driver configures a pvid of zero for each port, when in standalone mode. While the bridge configures a default_pvid of 1 for each port that gets added as a slave to it. 1. The bridge calls ocelot_port_vlan_filtering with vlan_aware=true. The VLAN-filtering-dependent portion of the native VLAN configuration is done, considering that the native VLAN is 0. 2. The bridge calls ocelot_vlan_add with vid=1, pvid=true, untagged=true. The native VLAN changes to 1 (change which gets propagated to hardware). 3. ??? - nobody calls ocelot_port_vlan_filtering again, to reapply the VLAN-filtering-dependent portion of the native VLAN configuration, for the new native VLAN of 1. One can notice that after toggling "ip link set dev br0 type bridge vlan_filtering 0 && ip link set dev br0 type bridge vlan_filtering 1", the new native VLAN finally makes it through and untagged traffic finally starts flowing again. But obviously that shouldn't be needed. So it is clear that 2 independent variables need to both re-trigger the native VLAN configuration. So we introduce the second variable as ocelot_port->vlan_aware. *Actually both the DSA Felix driver and the Ocelot driver already had each its own variable: - Ocelot: ocelot_port_private->vlan_aware - Felix: dsa_port->vlan_filtering but the common Ocelot library needs to work with a single, common, variable, so there is some refactoring done to move the vlan_aware property from the private structure into the common ocelot_port structure. Fixes: 97bb69e1e36e ("net: mscc: ocelot: break apart ocelot_vlan_port_apply") Signed-off-by: Vladimir Oltean Reviewed-by: Horatiu Vultur Signed-off-by: David S. Miller --- include/soc/mscc/ocelot.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/soc/mscc/ocelot.h') diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h index ebffcb36a7e3..6d6a3947c8b7 100644 --- a/include/soc/mscc/ocelot.h +++ b/include/soc/mscc/ocelot.h @@ -476,6 +476,8 @@ struct ocelot_port { void __iomem *regs; + bool vlan_aware; + /* Ingress default VLAN (pvid) */ u16 pvid; @@ -610,7 +612,7 @@ int ocelot_port_bridge_leave(struct ocelot *ocelot, int port, int ocelot_fdb_dump(struct ocelot *ocelot, int port, dsa_fdb_dump_cb_t *cb, void *data); int ocelot_fdb_add(struct ocelot *ocelot, int port, - const unsigned char *addr, u16 vid, bool vlan_aware); + const unsigned char *addr, u16 vid); int ocelot_fdb_del(struct ocelot *ocelot, int port, const unsigned char *addr, u16 vid); int ocelot_vlan_add(struct ocelot *ocelot, int port, u16 vid, bool pvid, -- cgit