From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Mon, 18 Nov 2019 20:16:57 +0200
Subject: net: dsa: felix: Fix CPU port assignment when not last port
Git-commit: b8fc7177d8aef1cc9c83b98e29097861adc84b49
Patch-mainline: v5.5-rc1
References: jsc#SLE-9263
On the NXP LS1028A, there are 2 Ethernet links between the Felix switch
and the ENETC:
- eno2 <-> swp4, at 2.5G
- eno3 <-> swp5, at 1G
Only one of the above Ethernet port pairs can act as a DSA link for
tagging.
When adding initial support for the driver, it was tested only on the 1G
eno3 <-> swp5 interface, due to the necessity of using PHYLIB initially
(which treats fixed-link interfaces as emulated C22 PHYs, so it doesn't
support fixed-link speeds higher than 1G).
After making PHYLINK work, it appears that swp4 still can't act as CPU
port. So it looks like ocelot_set_cpu_port was being called for swp4,
but then it was called again for swp5, overwriting the CPU port assigned
in the DT.
It appears that when you call dsa_upstream_port for a port that is not
defined in the device tree (such as swp5 when using swp4 as CPU port),
its dp->cpu_dp pointer is not initialized by dsa_tree_setup_default_cpu,
and this trips up the following condition in dsa_upstream_port:
if (!cpu_dp)
return port;
So the moral of the story is: don't call dsa_upstream_port for a port
that is not defined in the device tree, and therefore its dsa_port
structure is not completely initialized (ds->num_ports is still 6).
Fixes: 56051948773e ("net: dsa: ocelot: add driver for Felix switch family")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
drivers/net/dsa/ocelot/felix.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index 05e3f2898bf6..ce3637b504dd 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -286,7 +286,7 @@ static int felix_setup(struct dsa_switch *ds)
for (port = 0; port < ds->num_ports; port++) {
ocelot_init_port(ocelot, port);
- if (port == dsa_upstream_port(ds, port))
+ if (dsa_is_cpu_port(ds, port))
ocelot_set_cpu_port(ocelot, port,
OCELOT_TAG_PREFIX_NONE,
OCELOT_TAG_PREFIX_LONG);
--
2.16.4