Re: [PATCH net-next v14 05/10] net: phy: Represent PHY-less SFP modules with phy_port

[Maxime Chevallier]

Hi,

On 7/20/26 19:48, Maxime Chevallier wrote:
> Now that the SFP bus infrastructure notifies when PHY-less modules are
> connected, we can create a phy_port to represent it. Instead of letting
> the SFP subsystem handle that, the Bus' upstream is in charge of
> maintaining that phy_port and register it to the topology, as the
> upstream (in this case a phy device) is directly interacting with the
> underlying net_device.
> 
> Add a phy_caps helper to get the achievable modes on this module based
> on what the phy_port representing the bus supports.
> 
> Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
> Signed-off-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>

Sashiko NIPA says :

"
Can re-attaching a phy_device that owns an SFP cage with an inserted
PHY-less module to a different netdev corrupt the destination topology?
The mod_port is created during module_start and lives until module_stop,
so it survives phy_detach on the original netdev. On phy_detach, only
phy_link_topo_del_port() is called, but phydev->mod_port and
mod_port->id are left as-is
"

That's not possible, we can't detach a port and attach it to another netdev.
the port->id is kept accross topo remove/add to keep a consistent ID in
case we detach the port's parent at link-down.

Maxime