Introduce vendor-specific PHY tunable identifiers to control the
KSZ87xx low-loss cable erratum handling through the ethtool PHY
tunable interface.
The following tunables are added:
- a boolean "short-cable" tunable, applying a documented and
conservative preset intended for short or low-loss Ethernet cables;
- an integer LPF bandwidth tunable, allowing advanced adjustment of the
receiver low-pass filter bandwidth;
- an integer DSP EQ initial value tunable, allowing advanced tuning of
the PHY equalizer initialization.
The actual behavior is implemented by the corresponding PHY and switch
drivers.
Reviewed-by: Marek Vasut <marex@nabladev.com>
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Signed-off-by: Fidelio Lawson <fidelio.lawson@exotec.com>
Link: https://patch.msgid.link/20260609-ksz87xx_errata_low_loss_connections-v10-2-9ba4418cf3db@exotec.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fidelio Lawson
13655144dd