target/linux/generic/backport-5.4/707-v5.7-0006-net-dsa-b53-Prevent-tagged-VLAN-on-port-7-for-7278.patch

   1 From 88631864da093377ce6d5e60b5639328622a8e5c Mon Sep 17 00:00:00 2001
   2 From: Florian Fainelli <f.fainelli@gmail.com>
   3 Date: Mon, 30 Mar 2020 14:38:48 -0700
   4 Subject: [PATCH] net: dsa: b53: Prevent tagged VLAN on port 7 for 7278
   5
   6 On 7278, port 7 of the switch connects to the ASP UniMAC which is not
   7 capable of processing VLAN tagged frames. We can still allow the port to
   8 be part of a VLAN entry, and we may want it to be untagged on egress on
   9 that VLAN because of that limitation.
  10
  11 Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
  12 Signed-off-by: David S. Miller <davem@davemloft.net>
  13 ---
  14  drivers/net/dsa/b53/b53_common.c | 8 ++++++++
  15  1 file changed, 8 insertions(+)
  16
  17 --- a/drivers/net/dsa/b53/b53_common.c
  18 +++ b/drivers/net/dsa/b53/b53_common.c
  19 @@ -1366,6 +1366,14 @@ int b53_vlan_prepare(struct dsa_switch *
  20         if ((is5325(dev) || is5365(dev)) && vlan->vid_begin == 0)
  21                 return -EOPNOTSUPP;
  22
  23 +       /* Port 7 on 7278 connects to the ASP's UniMAC which is not capable of
  24 +        * receiving VLAN tagged frames at all, we can still allow the port to
  25 +        * be configured for egress untagged.
  26 +        */
  27 +       if (dev->chip_id == BCM7278_DEVICE_ID && port == 7 &&
  28 +           !(vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED))
  29 +               return -EINVAL;
  30 +
  31         if (vlan->vid_end >= dev->num_vlans)
  32                 return -ERANGE;
  33