On Sat, Oct 10, 2020 at 3:54 PM Ido Schimmel <idosch@idosch.org> wrote:

> Add 'ETHTOOL_A_LINKMODES_LANES' attribute and expand 'struct
> ethtool_link_settings' with lanes field in order to implement a new
> lanes-selector that will enable the user to advertise a specific number
> of lanes as well.

Why can't this be implied by port break-out configuration? For higher
speed signalling modes like PAM4, what's the difference between a
port with unused lanes vs the same port split into multiple logical
ports? In essence, the driver could then always choose the slowest
signalling mode that utilizes all the available lanes.

Regards,
Edwin Peer