[PATCH 5.10 2/5] net: dsa: microchip: ksz8795: Fix PVID tag insertion

Ben Hutchings
2021-08-16T18:09:58Z

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>
---
drivers/net/dsa/microchip/ksz8795.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 108a14db1f1a..3d36ffff1f4e 100644
--- 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,
--
2.20.1