[PATCH net-next] net: mctp: Expose transport binding identifier via IFLA attribute

[Khang D Nguyen]

On 08/11/2024 11:41, Jakub Kicinski wrote:
> On Tue,  5 Nov 2024 14:19:15 +0700 Khang Nguyen wrote:
>> However, we currently have no means to get this information from MCTP
>> links.
> 
> I'm not opposed to the netlink attribute, but to be clear this info
> is indirectly available in sysfs, right? We link the netdev to
> the parent device so the type of /sys/class/net/$your_ifc/device
> should reveal what the transport is?

Good point, I did not think about using the parent device, that would be 
a good workaround for the currently supported interfaces.

For the long term, we should still need the attribute. For example, 
vendor-defined transports need their 0xFF code, which cannot be derived 
anywhere. Or binding implementations that have parent SoC platform 
devices from the device tree, which do not always have a clear type 
shown in the sysfs...

(The MCTP-over-serial binding also does not have a parent device 
currently, but I believe we can fix that if necessary)