net: dsa: microchip: ksz8795: Fix PVID tag insertion

commit ef3b02a1d79b691f9a354c4903cf1e6917e315f9 upstream.

ksz8795 has never actually enabled PVID tag insertion, and it also
programmed the PVID incorrectly.  To fix this:

* Allow tag insertion to be controlled per ingress port.  On most
  chips, set bit 2 in Global Control 19.  On KSZ88x3 this control
  flag doesn't exist.

* When adding a PVID:
  - Set the appropriate register bits to enable tag insertion on
    egress at every other port if this was the packet's ingress port.
  - Mask *out* the VID from the default tag, before or-ing in the new
    PVID.

* When removing a PVID:
  - Clear the same control bits to disable tag insertion.
  - Don't update the default tag.  This wasn't doing anything useful.

Fixes: e66f840c08a2 ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backport to 5.10:
 - Drop the KSZ88x3 cases as those chips are not supported here
 - Handle VID ranges in ksz8795_port_vlan_del()]
Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 108a14db1f1a84a99c50d7fb91ccb15ef4477cdd..3d36ffff1f4e3ab234621620eb25ce08885613d3 100644 (file)
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -833,9 +833,11 @@ static void ksz8795_port_vlan_add(struct dsa_switch *ds, int port,
 
        if (new_pvid) {
                ksz_pread16(dev, port, REG_PORT_CTRL_VID, &vid);
-               vid &= 0xfff;
+               vid &= ~VLAN_VID_MASK;
                vid |= new_pvid;
                ksz_pwrite16(dev, port, REG_PORT_CTRL_VID, vid);
+
+               ksz_pwrite8(dev, port, REG_PORT_CTRL_12, 0x0f);
        }
 }
 
@@ -844,8 +846,9 @@ static int ksz8795_port_vlan_del(struct dsa_switch *ds, int port,
 {
        bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
        struct ksz_device *dev = ds->priv;
-       u16 data, vid, pvid, new_pvid = 0;
+       u16 data, vid, pvid;
        u8 fid, member, valid;
+       bool del_pvid = false;
 
        ksz_pread16(dev, port, REG_PORT_CTRL_VID, &pvid);
        pvid = pvid & 0xFFF;
@@ -865,14 +868,14 @@ static int ksz8795_port_vlan_del(struct dsa_switch *ds, int port,
                }
 
                if (pvid == vid)
-                       new_pvid = 1;
+                       del_pvid = true;
 
                ksz8795_to_vlan(fid, member, valid, &data);
                ksz8795_w_vlan_table(dev, vid, data);
        }
 
-       if (new_pvid != pvid)
-               ksz_pwrite16(dev, port, REG_PORT_CTRL_VID, pvid);
+       if (del_pvid)
+               ksz_pwrite8(dev, port, REG_PORT_CTRL_12, 0x00);
 
        return 0;
 }
@@ -1085,6 +1088,8 @@ static int ksz8795_setup(struct dsa_switch *ds)
 
        ksz_cfg(dev, S_MIRROR_CTRL, SW_MIRROR_RX_TX, false);
 
+       ksz_cfg(dev, REG_SW_CTRL_19, SW_INS_TAG_ENABLE, true);
+
        /* set broadcast storm protection 10% rate */
        regmap_update_bits(dev->regmap[1], S_REPLACE_VID_CTRL,
                           BROADCAST_STORM_RATE,