From: Vladimir Oltean vladimir.oltean@nxp.com
stable inclusion from stable-5.10.54 commit c8ebf135c1996e60a28be269e6fdaf9b46e1ff99 bugzilla: 175586 https://gitee.com/openeuler/kernel/issues/I4DVDU
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit e40cba9490bab1414d45c2d62defc0ad4f6e4136 ]
This simple series of commands:
ip link add br0 type bridge vlan_filtering 1 ip link set swp0 master br0
fails on sja1105 with the following error: [ 33.439103] sja1105 spi0.1: vlan-lookup-table needs to have at least the default untagged VLAN [ 33.447710] sja1105 spi0.1: Invalid config, cannot upload Warning: sja1105: Failed to change VLAN Ethertype.
For context, sja1105 has 3 operating modes: - SJA1105_VLAN_UNAWARE: the dsa_8021q_vlans are committed to hardware - SJA1105_VLAN_FILTERING_FULL: the bridge_vlans are committed to hardware - SJA1105_VLAN_FILTERING_BEST_EFFORT: both the dsa_8021q_vlans and the bridge_vlans are committed to hardware
Swapping out a VLAN list and another in happens in sja1105_build_vlan_table(), which performs a delta update procedure. That function is called from a few places, notably from sja1105_vlan_filtering() which is called from the SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING handler.
The above set of 2 commands fails when run on a kernel pre-commit 8841f6e63f2c ("net: dsa: sja1105: make devlink property best_effort_vlan_filtering true by default"). So the priv->vlan_state transition that takes place is between VLAN-unaware and full VLAN filtering. So the dsa_8021q_vlans are swapped out and the bridge_vlans are swapped in.
So why does it fail?
Well, the bridge driver, through nbp_vlan_init(), first sets up the SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING attribute, and only then proceeds to call nbp_vlan_add for the default_pvid.
So when we swap out the dsa_8021q_vlans and swap in the bridge_vlans in the SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING handler, there are no bridge VLANs (yet). So we have wiped the VLAN table clean, and the low-level static config checker complains of an invalid configuration. We _will_ add the bridge VLANs using the dynamic config interface, albeit later, when nbp_vlan_add() calls us. So it is natural that it fails.
So why did it ever work?
Surprisingly, it looks like I only tested this configuration with 2 things set up in a particular way: - a network manager that brings all ports up - a kernel with CONFIG_VLAN_8021Q=y
It is widely known that commit ad1afb003939 ("vlan_dev: VLAN 0 should be treated as "no vlan tag" (802.1p packet)") installs VID 0 to every net device that comes up. DSA treats these VLANs as bridge VLANs, and therefore, in my testing, the list of bridge_vlans was never empty.
However, if CONFIG_VLAN_8021Q is not enabled, or the port is not up when it joins a VLAN-aware bridge, the bridge_vlans list will be temporarily empty, and the sja1105_static_config_reload() call from sja1105_vlan_filtering() will fail.
To fix this, the simplest thing is to keep VID 4095, the one used for CPU-injected control packets since commit ed040abca4c1 ("net: dsa: sja1105: use 4095 as the private VLAN for untagged traffic"), in the list of bridge VLANs too, not just the list of tag_8021q VLANs. This ensures that the list of bridge VLANs will never be empty.
Fixes: ec5ae61076d0 ("net: dsa: sja1105: save/restore VLANs using a delta commit method") Reported-by: Radu Pirea (NXP OSS) radu-nicolae.pirea@oss.nxp.com Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- drivers/net/dsa/sja1105/sja1105_main.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c index 82852c57cc0e..82b918d36117 100644 --- a/drivers/net/dsa/sja1105/sja1105_main.c +++ b/drivers/net/dsa/sja1105/sja1105_main.c @@ -350,6 +350,12 @@ static int sja1105_init_static_vlan(struct sja1105_private *priv) if (dsa_is_cpu_port(ds, port)) v->pvid = true; list_add(&v->list, &priv->dsa_8021q_vlans); + + v = kmemdup(v, sizeof(*v), GFP_KERNEL); + if (!v) + return -ENOMEM; + + list_add(&v->list, &priv->bridge_vlans); }
((struct sja1105_vlan_lookup_entry *)table->entries)[0] = pvid;