I was trying to fix the lan966x driver [1] which doesn't work if there
are disabled nodes in between.
Can you elaborate what's wrong now in the behaviour of the driver? In
the code it uses twice the _available variant.
Imagine the following device tree snippet:
port0 {
reg = <0>;
status = "okay";
}
port1 {
reg = <1>;
status = "disabled";
}
port@2 {
reg = <2>;
status = "okay";
}
The driver will set num_phys_ports to 2. When port@2 is probed, it
will have the (correct!) physical port number 2. That will then
trigger various EINVAL checks with "port_num >= num_phys_ports" or
WARN()s.
So the easiest fix would be to actual count all the child nodes
(regardless if they are available or not), assuming there are as
many nodes as physical ports.
But num_phys_ports being a property of the hardware I don't
think it's good to deduce it by counting the child nodes anyway,
but it should rather be a (hardcoded) property of the driver.
-michael
[1]
https://elixir.bootlin.com/linux/v5.19-rc4/source/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
