From 93a32fc4f43ae40a2140acd9258faada11a98ec0 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Mon, 18 Nov 2019 20:16:57 +0200 Subject: [PATCH] net: dsa: felix: Fix CPU port assignment when not last port 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 Signed-off-by: David S. Miller --- drivers/net/dsa/ocelot/felix.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- 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 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);