Re: [EXT] Re: [PATCH] bus: fsl-mc: Add ACPI support for fsl-mc

On Sat, 1 Feb 2020 11:49:19 +0000, Russell King - ARM Linux admin wrote:

What if someone decides to do:

	devlink port split device/1 count 2

what do we end up with?  Presumably two network devices running with
two serdes lanes each (if supported by the hardware).  At that point
can they then do:

	devlink port split device/2 count 2

and end up with one network device with two 10G serdes lanes, and two
network devices each with one 10G serdes lane, 

I think all your guesses are correct, it's a pretty straight forward
API, but it's also pretty thin, and some of the logic is in FW, so
there isn't much in a way of a standard on how things should behave :S

or can port splitting only be used on the "master" device/port ?

I think both mlxsw and the NFP rejects re-split/further splitting.
Ports have to be unsplit first. So there is only one device for
splitting, and unsplitting can be done on any of the sub-devices.

Unfortunately, I don't think I have any network devices that support
this so I can't experiment to find out how this should work; yes, I
have a Mellanox card, but it supports a single 10G SFP+, and therefore
does not support port splitting.

I think you'd need a mlxsw or an nfp to play with this.

Maybe Jiri can clarify further :)