> > $ ethtool --set-module enp1s0f0np0 power-max-set 4000
> >
> > actually talk to the SFP module and tell it the maximum power it can
> > consume. So in this case, it is not the cage, but the module?
>
> It does not work that way in ice example.
> >
> > Or is it talking to some entity which is managing the overall power
> > consumption of a number of cages, and asking it to allocate a maximum
> > of 4W to this cage. It might return an error message saying there is
> > no power budget left?
>
> That's right, we talk to firmware to set those restrictions.
> In the ice implementation, the driver is responsible for checking if the
> overall board budget is not exceeded.
So i can get the board to agree that the cage can supply 3W to the
module, but how do i then tell the module this?
I would also suggest you don't focus too much on ICE. I find it better
to think about an abstract system. A board with a power supply to a
number of SFP cages, and some cages have modules in them. What does
the kAPI look like, the use cases for this abstract system.
Andrew
