target/linux/generic/backport-5.10/741-v5.14-0001-net-dsa-b53-Do-not-force-CPU-to-be-always-tagged.patch

   1 From 2c32a3d3c233b855943677609fe388f82b1f0975 Mon Sep 17 00:00:00 2001
   2 From: Florian Fainelli <f.fainelli@gmail.com>
   3 Date: Tue, 8 Jun 2021 14:22:04 -0700
   4 Subject: [PATCH] net: dsa: b53: Do not force CPU to be always tagged
   5
   6 Commit ca8931948344 ("net: dsa: b53: Keep CPU port as tagged in all
   7 VLANs") forced the CPU port to be always tagged in any VLAN membership.
   8 This was necessary back then because we did not support Broadcom tags
   9 for all configurations so the only way to differentiate tagged and
  10 untagged traffic while DSA_TAG_PROTO_NONE was used was to force the CPU
  11 port into being always tagged.
  12
  13 With most configurations enabling Broadcom tags, especially after
  14 8fab459e69ab ("net: dsa: b53: Enable Broadcom tags for 531x5/539x
  15 families") we do not need to apply this unconditional force tagging of
  16 the CPU port in all VLANs.
  17
  18 A helper function is introduced to faciliate the encapsulation of the
  19 specific condition requiring the CPU port to be tagged in all VLANs and
  20 the dsa_switch_ops::untag_bridge_pvid boolean is moved to when
  21 dsa_switch_ops::setup is called when we have already determined the
  22 tagging protocol we will be using.
  23
  24 Reported-by: Matthew Hagan <mnhagan88@gmail.com>
  25 Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
  26 Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
  27 Tested-by: Matthew Hagan <mnhagan88@gmail.com>
  28 Signed-off-by: David S. Miller <davem@davemloft.net>
  29 ---
  30  drivers/net/dsa/b53/b53_common.c | 17 ++++++++++++++---
  31  1 file changed, 14 insertions(+), 3 deletions(-)
  32
  33 --- a/drivers/net/dsa/b53/b53_common.c
  34 +++ b/drivers/net/dsa/b53/b53_common.c
  35 @@ -1049,6 +1049,11 @@ static int b53_setup(struct dsa_switch *
  36         unsigned int port;
  37         int ret;
  38
  39 +       /* Request bridge PVID untagged when DSA_TAG_PROTO_NONE is set
  40 +        * which forces the CPU port to be tagged in all VLANs.
  41 +        */
  42 +       ds->untag_bridge_pvid = dev->tag_protocol == DSA_TAG_PROTO_NONE;
  43 +
  44         ret = b53_reset_switch(dev);
  45         if (ret) {
  46                 dev_err(ds->dev, "failed to reset switch\n");
  47 @@ -1423,6 +1428,13 @@ int b53_vlan_prepare(struct dsa_switch *
  48         return 0;
  49  }
  50  EXPORT_SYMBOL(b53_vlan_prepare);
  51 +
  52 +static bool b53_vlan_port_needs_forced_tagged(struct dsa_switch *ds, int port)
  53 +{
  54 +       struct b53_device *dev = ds->priv;
  55 +
  56 +       return dev->tag_protocol == DSA_TAG_PROTO_NONE && dsa_is_cpu_port(ds, port);
  57 +}
  58
  59  void b53_vlan_add(struct dsa_switch *ds, int port,
  60                   const struct switchdev_obj_port_vlan *vlan)
  61 @@ -1442,7 +1454,7 @@ void b53_vlan_add(struct dsa_switch *ds,
  62                         untagged = true;
  63
  64                 vl->members |= BIT(port);
  65 -               if (untagged && !dsa_is_cpu_port(ds, port))
  66 +               if (untagged && !b53_vlan_port_needs_forced_tagged(ds, port))
  67                         vl->untag |= BIT(port);
  68                 else
  69                         vl->untag &= ~BIT(port);
  70 @@ -1480,7 +1492,7 @@ int b53_vlan_del(struct dsa_switch *ds,
  71                 if (pvid == vid)
  72                         pvid = b53_default_pvid(dev);
  73
  74 -               if (untagged && !dsa_is_cpu_port(ds, port))
  75 +               if (untagged && !b53_vlan_port_needs_forced_tagged(ds, port))
  76                         vl->untag &= ~(BIT(port));
  77
  78                 b53_set_vlan_entry(dev, vid, vl);
  79 @@ -2644,7 +2656,6 @@ struct b53_device *b53_switch_alloc(stru
  80         dev->ops = ops;
  81         ds->ops = &b53_switch_ops;
  82         ds->configure_vlan_while_not_filtering = true;
  83 -       ds->untag_bridge_pvid = true;
  84         dev->vlan_enabled = ds->configure_vlan_while_not_filtering;
  85         /* Let DSA handle the case were multiple bridges span the same switch
  86          * device and different VLAN awareness settings are requested, which