On Wed, 29 Jun 2022 13:51:43 +0100
"Russell King (Oracle)" [off-list ref] wrote:

Currently, we only use phylink for CPU and DSA ports if there is a
fixed-link specification, or a PHY specified. The reason for this
behaviour is that when neither is specified, there was no way for
phylink to know the link parameters.

Now that we have phylink_set_max_link_speed() (which has become
possible through the addition of mac_capabilities) we now have the
ability to know the maximum link speed for a specific link, and can
now use phylink for this case as well.

However, we need DSA drivers to report the interface mode being used
on these ports so that we can select a maximum speed appropriate for
the interface mode that hardware may have configured for the port.

This is especially important with the conversion of DSA drivers to
phylink_pcs, as the PCS code only gets called if we are using
phylink for the port.

Signed-off-by: Russell King (Oracle) <redacted>

Reviewed-by: Marek Behún <kabel@kernel.org>

So this is the one that may break other drivers?

Marek