On 8/8/22 12:57, Sean Anderson wrote:
Hi Tim,
On 8/8/22 3:18 PM, Tim Harvey wrote:
Greetings,
I'm trying to understand if there is any implication of 'ethernet<n>'
aliases in Linux such as:
aliases {
ethernet0 = &eqos;
ethernet1 = &fec;
ethernet2 = &lan1;
ethernet3 = &lan2;
ethernet4 = &lan3;
ethernet5 = &lan4;
ethernet6 = &lan5;
};
I know U-Boot boards that use device-tree will use these aliases to
name the devices in U-Boot such that the device with alias 'ethernet0'
becomes eth0 and alias 'ethernet1' becomes eth1 but for Linux it
appears that the naming of network devices that are embedded (ie SoC)
vs enumerated (ie pci/usb) are always based on device registration
order which for static drivers depends on Makefile linking order and
has nothing to do with device-tree.
Is there currently any way to control network device naming in Linux
other than udev?
You can also use systemd-networkd et al. (but that is the same kind of mechanism)
Does Linux use the ethernet<n> aliases for anything at all?
No :l
It is actually used, but by individual drivers, not by the networking
stack AFAICT:
git grep -E "of_alias_get_id\((.*), \"(eth|ethernet)\"\)" *
drivers/net/ethernet/broadcom/genet/bcmmii.c: id =
of_alias_get_id(dn, "eth");
drivers/net/ethernet/samsung/sxgbe/sxgbe_platform.c: plat->bus_id =
of_alias_get_id(np, "ethernet");
drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c: plat->bus_id =
of_alias_get_id(np, "ethernet");
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c: plat->bus_id =
of_alias_get_id(np, "ethernet");
There were discussions about using that alias to name ethernet network
devices in the past (cannot quite point to the thread), the current
consensus appears to be that if you use the "label" property (which was
primed by DSA) then your network device will follow that name, still not
something the networking stack does for you within the guts of
register_netdev().
--
Florian
